Section headers don't look like headers in Sphinx theme

[kyleabeauchamp]

For example, the Notes section on the tICA class page:

http://msmbuilder.org/api/generated/msmbuilder.reduce.tICA.tICA.html#msmbuilder.reduce.tICA.tICA

I think this is a general problem with the available themes for Sphinx, as it seems that the default sphinx theme uses bold but several other themes (including the ReadTheDocs theme) uses plaintext for headers.

[kyleabeauchamp]

FWIW, I think the sklearn theme does a better job on this:

http://scikit-learn.org/stable/modules/generated/sklearn.cluster.KMeans.html#sklearn.cluster.KMeans

[kyleabeauchamp]

Here's another example of how our theme is "bad":

http://mdtraj.org/latest/api/generated/mdtraj.utils.ensure_type.html#mdtraj.utils.ensure_type