Try reinstating per-release permalinks

[bitprophet]

Looks like I overlooked the handy permalinks you get with title docutils nodes, when trying to restyle the release-header H2's.

They appear on other, regular titles as e.g. <a class="headerlink" href="#changelog" title="Permalink to this headline">¶</a>.

The targets seem to automagically work still - i.e. the div IDs function, so you can go to a new-style Releases changelog and slap #1.2.3 to the URL and it works right.

But that's effectively invisible to users now.