Add changelog

CHANGELOG.rst

@@ -7,6 +7,14 @@ The format is based on `Keep a Changelog`_,
 and this project adheres to `Semantic Versioning`_.
 
 
+Unreleased
+----------
+
+Fixed
+~~~~~
+
+* The Matrix groups and rooms threw a 404 error.
+
 `2.0b0` - 2023-02-23
 --------------------