Whilst working on the Reproducible Builds effort [0], we noticed
that pylint could not be built reproducibly.
This is due to the documentation generator iterating over the filesystem
in a nondeterminstic order and then iterating over an internal,
nondeterminstic, data structure.
This was originally filed in Debian as #883913.
[0] https://reproducible-builds.org/
[1] https://bugs.debian.org/883913
Signed-off-by: Chris Lamb <chris@chris-lamb.co.uk>
Currently we can generate this locally using the makefiles, but, unfortunately,
on ReadThedocs we are running only sphinx-build, which means that we have no
pre-generated features.rst file before actually building the documentation.
This commit just adds one, which does the same thing as the makefiles.
