Rollup merge of rust-lang#23317 - tanadeau:fix-formatting-and-grammar, r=steveklabnik

 Fixed grammar errors (incorrect uses of commas and \"you're\" instead of \"your\") and broke up a long line.

r? @steveklabnik

Author: Manishearth

src/doc/trpl/hello-cargo.md

@@ -85,9 +85,11 @@ Hello, world!
 Bam! We build our project with `cargo build`, and run it with
 `./target/debug/hello_world`. This hasn't bought us a whole lot over our simple use
 of `rustc`, but think about the future: when our project has more than one
-file, we would need to call `rustc` more than once, and pass it a bunch of options to
+file, we would need to call `rustc` more than once and pass it a bunch of options to
 tell it to build everything together. With Cargo, as our project grows, we can
-just `cargo build` and it'll work the right way. When you're project is finally ready for release, you can use `cargo build --release` to compile your crates with optimizations.
+just `cargo build`, and it'll work the right way. When your project is finally
+ready for release, you can use `cargo build --release` to compile your crates with
+optimizations.
 
 You'll also notice that Cargo has created a new file: `Cargo.lock`.