update readme

README.rst

@@ -33,13 +33,14 @@ Overview
 PyOTRS is a Python wrapper for accessing `OTRS <https://www.otrs.com/>`_ (Version 5 or 6) using the
 REST API.
 
-.. warning::
+Warning
+=======
 
     Please upgrade PyOTRS to atleast version 0.7.0 if you are using OTRS 6.0.27, 7.0.16 or
-    newer! See `issue 27 <https://gitlab.com/rhab/PyOTRS/-/issues/27>`_ for more details.
+    newer. See `issue 27 <https://gitlab.com/rhab/PyOTRS/-/issues/27>`_ for more details.
 
 Features
---------
+========
 
 Access an OTRS instance to::