Be consistent about how "Edition differences" is capitalized

The existing text was inconsistent with whether or not the "d" was
capitalized. This goes the route of using a lowercase "d" to match the
style of using sentence-case for headings.

Author: ehuss

docs/authoring.md

@@ -154,4 +154,4 @@ The reference does not document which targets exist, or the properties of specif
 
 ### Editions
 
-The main text and flow should document only the current edition. Whenever there is a difference between editions, the differences should be called out with an "Edition Differences" block.
+The main text and flow should document only the current edition. Whenever there is a difference between editions, the differences should be called out with an "Edition differences" block.

src/expressions/method-call-expr.md

@@ -66,7 +66,7 @@ Once a method is looked up, if it can't be called for one (or more) of those rea
 If a step is reached where there is more than one possible method, such as where generic methods or traits are considered the same, then it is a compiler error.
 These cases require a [disambiguating function call syntax] for method and function invocation.
 
-> **Edition Differences**: Before the 2021 edition, during the search for visible methods, if the candidate receiver type is an [array type], methods provided by the standard library [`IntoIterator`] trait are ignored.
+> **Edition differences**: Before the 2021 edition, during the search for visible methods, if the candidate receiver type is an [array type], methods provided by the standard library [`IntoIterator`] trait are ignored.
 >
 > The edition used for this purpose is determined by the token representing the method name.
 >

src/introduction.md

@@ -82,9 +82,9 @@ These conventions are documented here.
 
   An *example term* is an example of a term being defined.
 
-* Differences in the language by which edition the crate is compiled under are in a blockquote that start with the words "Edition Differences:" in **bold**.
+* Differences in the language by which edition the crate is compiled under are in a blockquote that start with the words "Edition differences:" in **bold**.
 
-  > **Edition Differences**: In the 2015 edition, this syntax is valid that is disallowed as of the 2018 edition.
+  > **Edition differences**: In the 2015 edition, this syntax is valid that is disallowed as of the 2018 edition.
 
 * Notes that contain useful information about the state of the book or point out useful, but mostly out of scope, information are in blockquotes that start with the word "Note:" in **bold**.
 

src/items/associated-items.md

@@ -189,7 +189,7 @@ let circle_shape = Circle::new();
 let bounding_box = circle_shape.bounding_box();
 ```
 
-> **Edition Differences**: In the 2015 edition, it is possible to declare trait
+> **Edition differences**: In the 2015 edition, it is possible to declare trait
 > methods with anonymous parameters (e.g. `fn foo(u8)`). This is deprecated and
 > an error as of the 2018 edition. All parameters must have an argument name.
 

src/macros-by-example.md

@@ -148,7 +148,7 @@ the `expr` fragment specifier. However, `_` is matched by the `expr` fragment
 specifier when it appears as a subexpression.
 For the same reason, a standalone [const block] is not matched but it is matched when appearing as a subexpression.
 
-> **Edition Differences**: Starting with the 2021 edition, `pat` fragment-specifiers match top-level or-patterns (that is, they accept [_Pattern_]).
+> **Edition differences**: Starting with the 2021 edition, `pat` fragment-specifiers match top-level or-patterns (that is, they accept [_Pattern_]).
 >
 > Before the 2021 edition, they match exactly the same fragments as `pat_param` (that is, they accept [_PatternNoTopAlt_]).
 >
@@ -421,7 +421,7 @@ macro_rules! call_foo {
 fn foo() {}
 ```
 
-> **Version & Edition Differences**: Prior to Rust 1.30, `$crate` and
+> **Version & Edition differences**: Prior to Rust 1.30, `$crate` and
 > `local_inner_macros` (below) were unsupported. They were added alongside
 > path-based imports of macros (described above), to ensure that helper macros
 > did not need to be manually imported by users of a macro-exporting crate.
@@ -475,7 +475,7 @@ Matchers like `$i:expr,` or `$i:expr;` would be legal, however, because `,` and
     `ident`, `ty`, or `path` fragment specifier.
   * All other fragment specifiers have no restrictions.
 
-> **Edition Differences**: Before the 2021 edition, `pat` may also be followed by `|`.
+> **Edition differences**: Before the 2021 edition, `pat` may also be followed by `|`.
 
 When repetitions are involved, then the rules apply to every possible number of
 expansions, taking separators into account. This means:

src/names/preludes.md

@@ -44,7 +44,7 @@ new_name`, then the symbol `new_name` is instead added to the prelude.
 The [`core`] crate is always added to the extern prelude. The [`std`] crate is
 added as long as the [`no_std` attribute] is not specified in the crate root.
 
-> **Edition Differences**: In the 2015 edition, crates in the extern prelude
+> **Edition differences**: In the 2015 edition, crates in the extern prelude
 > cannot be referenced via [use declarations], so it is generally standard
 > practice to include `extern crate` declarations to bring them into scope.
 >
@@ -132,7 +132,7 @@ module or any of its descendants.
 
 This attribute does not affect the [language prelude].
 
-> **Edition Differences**: In the 2015 edition, the `no_implicit_prelude`
+> **Edition differences**: In the 2015 edition, the `no_implicit_prelude`
 > attribute does not affect the [`macro_use` prelude], and all macros exported
 > from the standard library are still included in the `macro_use` prelude.
 > Starting in the 2018 edition, it will remove the `macro_use` prelude.

src/paths.md

@@ -166,7 +166,7 @@ Paths starting with `::` are considered to be *global paths* where the segments
 start being resolved from a place which differs based on edition. Each identifier in
 the path must resolve to an item.
 
-> **Edition Differences**: In the 2015 Edition, identifiers resolve from the "crate root"
+> **Edition differences**: In the 2015 Edition, identifiers resolve from the "crate root"
 > (`crate::` in the 2018 edition), which contains a variety of different items, including
 > external crates, default crates such as `std` or `core`, and items in the top level of
 > the crate (including `use` imports).

src/patterns.md

@@ -533,7 +533,7 @@ For example, `0u8..=255u8` is irrefutable.
 The range of values for an integer type is the closed range from its minimum to maximum value.
 The range of values for a `char` type are precisely those ranges containing all Unicode Scalar Values: `'\u{0000}'..='\u{D7FF}'` and `'\u{E000}'..='\u{10FFFF}'`.
 
-> **Edition Differences**: Before the 2021 edition, range patterns with both a lower and upper bound may also be written using `...` in place of `..=`, with the same meaning.
+> **Edition differences**: Before the 2021 edition, range patterns with both a lower and upper bound may also be written using `...` in place of `..=`, with the same meaning.
 
 ## Reference patterns
 

src/tokens.md

@@ -375,7 +375,7 @@ c"\u{00E6}";
 c"\xC3\xA6";
 ```
 
-> **Edition Differences**: C string literals are accepted in the 2021 edition or
+> **Edition differences**: C string literals are accepted in the 2021 edition or
 > later. In earlier additions the token `c""` is lexed as `c ""`.
 
 #### Raw C string literals
@@ -400,7 +400,7 @@ encoding. The characters `U+0022` (double-quote) (except when followed by at
 least as many `U+0023` (`#`) characters as were used to start the raw C string
 literal) or `U+005C` (`\`) do not have any special meaning.
 
-> **Edition Differences**: Raw C string literals are accepted in the 2021
+> **Edition differences**: Raw C string literals are accepted in the 2021
 > edition or later. In earlier additions the token `cr""` is lexed as `cr ""`,
 > and `cr#""#` is lexed as `cr #""#` (which is non-grammatical).
 
@@ -735,7 +735,7 @@ Note that raw identifiers, raw string literals, and raw byte string literals may
 
 Similarly the `r`, `b`, `br`, `c`, and `cr` prefixes used in raw string literals, byte literals, byte string literals, raw byte string literals, C string literals, and raw C string literals are not interpreted as reserved prefixes.
 
-> **Edition Differences**: Starting with the 2021 edition, reserved prefixes are reported as an error by the lexer (in particular, they cannot be passed to macros).
+> **Edition differences**: Starting with the 2021 edition, reserved prefixes are reported as an error by the lexer (in particular, they cannot be passed to macros).
 >
 > Before the 2021 edition, reserved prefixes are accepted by the lexer and interpreted as multiple tokens (for example, one token for the identifier or keyword, followed by a `#` token).
 >

src/types/trait-object.md

@@ -31,13 +31,13 @@ For example, given a trait `Trait`, the following are all trait objects:
 * `dyn 'static + Trait`.
 * `dyn (Trait)`
 
-> **Edition Differences**: Before the 2021 edition, the `dyn` keyword may be
+> **Edition differences**: Before the 2021 edition, the `dyn` keyword may be
 > omitted.
 >
 > Note: For clarity, it is recommended to always use the `dyn` keyword on your
 > trait objects unless your codebase supports compiling with Rust 1.26 or lower.
 
-> **Edition Differences**: In the 2015 edition, if the first bound of the
+> **Edition differences**: In the 2015 edition, if the first bound of the
 > trait object is a path that starts with `::`, then the `dyn` will be treated
 > as a part of the path. The first path can be put in parenthesis to get
 > around this. As such, if you want a trait object with the trait

src/visibility-and-privacy.md

@@ -156,7 +156,7 @@ follows:
 - `pub(self)` makes an item visible to the current module. This is equivalent
 to `pub(in self)` or not using `pub` at all.
 
-> **Edition Differences**: Starting with the 2018 edition, paths for
+> **Edition differences**: Starting with the 2018 edition, paths for
 > `pub(in path)` must start with `crate`, `self`, or `super`. The 2015 edition
 > may also use paths starting with `::` or modules from the crate root.