Update CHANGELOG.md

Author: BruhDark

CHANGELOG.md

@@ -30,6 +30,8 @@ These changes are available on the `master` branch, but have not yet been releas
   ([#2587](https://github.com/Pycord-Development/pycord/pull/2587/))
 - Added optional `filter` parameter to `utils.basic_autocomplete()`.
   ([#2590](https://github.com/Pycord-Development/pycord/pull/2590))
+- Added missing `with_counts` parameter to `fetch_guilds` method.
+  ([#2615](https://github.com/Pycord-Development/pycord/pull/2615))
 
 ### Fixed