CHANGES: Document trailing slashes in routes, endpoint

CHANGES.rst

@@ -20,6 +20,9 @@ Changelog for Isso
 - Allow ``sup`` and ``sub`` HTML elements by default
 - Add ``data-isso-page-author-hashes`` option to client which makes it possible
   to style comments and replies made by the page's author(s).
+- Strip trailing slash from public-endpoint, allow trailing slashes for routes.
+  A trailing slash in ``[server] public-endpoint`` is now discouraged and
+  throws a warning (#876, ix5)
 
 .. _Gravatar: Image requests: http://en.gravatar.com/site/implement/images/