docs: add 5.1.0 to changelog.md

Author: LordOfPolls

docs/src/changelog.md

@@ -3,6 +3,16 @@
 Here you can find the changelog for the library. This is a list of all the changes that have been made to the library, since V5.0.0. 
 In breaking changes, the breaking change is signified by a `💥`
 
+## 5.1.0 - TBA
+- Feat: Add support for regex component callbacks
+- Feat: Add new audit log events to enums
+- Refactor: Change log level of missing enum value from error to warning
+- Feat: Add missing message types to enums
+- Feat: Add support for Avatar Decorations
+- Chore: Switch library license to MIT
+- Build: Add pypi alias `interactions.py`
+- Feat: Enhance cooldown system
+      - Adds new cooldown strategies and allows fetching of the cooldown object using an ID instead of context object
 
 ## 5.0.1 - April 12th, 2023
 - Fix: copy checks when inheriting