Convert code-of-conduct to rst

Convert code-of-conduct to rst

Underline section titles.

Convert links to RST-style links.  NB that the Communication Guide
link won't work ATM; this will be fixed when we convert that document
to RST.

Adjust the formatting for the list so that it's converted properly.

A couple of clean-ups:

* Expand the label for communication guidance, and convert the link to
the project governance to a named reference rather than an "embedded"
URI.

* Move all hyperlink targets to the bottom of the article, and put
  them in the order they're linked.

No changes to the text.

Signed-off-by: George Dunlap <george.dunlap@citrix.com>