* Copyedit the page
A few minor updates were made.
* Update conjuction
Three options. The first (original) was OK, the second (change in this PR) was ambiguous, the third is a bit clearer.
It was not clear what "Before you begin" meant and how it needs to be added only if the task or tutorial is version specific. Therefore, added this info in.
* Add info about requesting access
This includes how to get a sponsor, how to be a sponsor,
how to become a reviewer, approver, and website admin.
* Address feedback
* 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.