Make all parameter descriptions etc. use reStructuredText definition
lists with uniform style and indentation. Remove redundant indentation
from around the lists. Remove blank lines between term lines and
definition blocks. Use four spaces for indentation.
This is almost completely whitespace and paragraph reflow changes.
This is the output from sphinx-quickstart, massaged a bit, along with
our existing man pages converted to rst.
A skeleton notmuch-emacs manual is also included. It is not suitable
for end user use yet.