Update RELEASES.md

Co-authored-by: Joshua Nelson <jyn514@gmail.com>

Author: XAMPPRocky

RELEASES.md

@@ -11,6 +11,11 @@ Language
  ```rust
  #![doc = include_str!("README.md")]
  ```
+ You can also use this to include auto-generated modules:
+ ```rust
+ #[path = concat!(env!("OUT_DIR"), "/generated.rs")]
+ mod generated;
+ ```
 
 - [You can now cast between unsized slice types (and types which contain
  unsized slices) in `const fn`.][85078]