[x265] online documentation

[Steve Borho]

Hello,

We have migrated our documentation to restructured text
(http://sphinx-doc.org/rest.html) so that it can be maintained within
the source repository and follow the same release management processes
as the source code.

The goal going forward will be to keep the documentation up to date as
changes are made to the software (optimally in the same commits).

Right now the documentation only covers the CLI / x265_param_parse()
options. We would like to expand it to cover API documentation and
other topics. It can be found at:
http://x265.readthedocs.org/en/default

Going forward, there will also be
http://x265.readthedocs.org/en/stable holding documentation for the
current stable branch, and there will be per-release labels. For
instance, when 0.9 is tagged there will be a page named
http://x265.readthedocs.org/en/0.9

Feedback is welcome for these web pages, patches even more so. The
document source is easily edited text files, see
https://bitbucket.org/multicoreware/x265/raw/tip/doc/reST/cli.rst

-- 
Steve Borho