message: Fix capitalisation in the changelog
diff: Features
  --------
  -- Render matrix message edits as sed-like diff statements, falling back to asterisk formatted messages ([\#1465](https://github.com/matrix-org/matrix-appservice-irc/issues/1465))
  +- Render Matrix message edits as sed-like diff statements, falling back to asterisk formatted messages ([\#1465](https://github.com/matrix-org/matrix-appservice-irc/issues/1465))
  Bugfixes
  