fix subheading in contributing.rst
@@ -247,7 +247,7 @@ guidelines to follow:
with the ``logging`` module, feed it through this function.
Editor Settings
-^^^^^^^^^^^^^^^
+---------------
Personally, I work on beets with `vim <http://www.vim.org/>`__. Here are
some ``.vimrc`` lines that might help with PEP 8-compliant Python
