Update CHANGELOG.md

Author: TyrantLink

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 `store_poll` method to `Webhook._WebhookState`.
+  ([#2624](https://github.com/Pycord-Development/pycord/pull/2624))
 
 ### Fixed