* [Website] Add titles and labels to iframes and images on Community pages
**what is the change?:**
- add titles to all iframes
- add alt tags to images
- add `aria-label` to some links which only have images as contents.
**why make this change?:**
Based on warnings thrown by aXe a11y audit of those pages
**test plan:**
Manual testing
**issue:**
None
* remove redundant alt tags
Adds a new docs website, built with Gatsby JS, to replace the old Jekyll site. Source code for the new site lives in /www (although markdown and YML data still comes from the legacy /docs folder).
Changes to either markdown or website source code can be previewed on Netlify. The react-js bot should automatically add comments to each PR with preview links. (This preview is generated by running the newly-added yarn build:docs command in the root package.json.)
The majority of the changes in this PR are contained within the new /www directory. However some minor modifications have been made to existing content in the /docs directory:
* Modified frontmatter author block to always be an array
* Small markdown formatting tweaks
Matthew Holman
Brian Vaughn
Flarnie Marchan
brillout
Kevin Lacker