* Add instructions for staging site using Docker
Adds a condensed version of the instructions in the README to
the intermediate contribution page.
* Format code blocks
* Reorganize docs contrib guide
* Address first round of feedback from Brad, Jared
* Standardize on 'SIG Docs'
* Address more feedback
* Rewrites to participating.md
* Tweak navigation titles
* Document PR Wrangler
* Document SIG Docs chairperson
* Fix codeblock that shows how to use <codenew>
It was being interpreted as a Hugo shortcode.
Misty Linville
Tim Fogarty
shavidissa
Sam Foo