Update RELEASE_NOTES.md

Author: caendesilva

RELEASE_NOTES.md

@@ -14,6 +14,7 @@ This serves two purposes:
 
 ### Changed
 - Updated 404 page home link to use the index route instead of the site URL https://github.com/hydephp/develop/pull/1278
+- Improved generic type usage in the RegisterFileLocations trait https://github.com/hydephp/develop/pull/1279
 
 ### Deprecated
 - for soon-to-be removed features.