Improve appearance of table of contents with reST

Tables of contents with reST are currently ugly.  (See, e.g., [this](https://github.com/rschroll/prsannots/blob/master/README.rst).)  There are several problems; one of them is that the top-level heading is included in the table of contents, even if it is acting as a header.  Turning doctitle_xform on fixes that, but makes the next-lower header rise up to &lt;h1>.  Changing initial_header_level pushes it back to &lt;h2>.