Fix formatting of return from main types list

Author: Havvy

src/attributes.md

@@ -233,8 +233,8 @@ attribute must take no arguments, must not declare any
 type must be one of the following:
 
 * `()`
-<!-- * `!` -->
 * `Result<(), E> where E: Error`
+<!-- * `!` -->
 <!-- * Result<!, E> where E: Error` -->
 
 > Note: The implementation of which return types are allowed is determined by

src/crates-and-source-files.md

@@ -72,8 +72,8 @@ A crate that contains a `main` [function] can be compiled to an executable. If a
 type must  be one of the following:
 
 * `()`
-<!-- * `!` -->
 * `Result<(), E> where E: Error`
+<!-- * `!` -->
 <!-- * Result<!, E> where E: Error` -->
 
 > Note: The implementation of which return types are allowed is determined by