Consider adding feedback routes for documentation pages

[StevenMaude]

mkdocs-material has a means for adding a user feedback widget.

In the docs for mkdocs-material, someone responding "no" to the "Was this page helpful?" prompt at the bottom of a page gets a prompt to fill in a Google Form to supply detailed feedback. This is currently an "insider" only feature: we'd have to wait for a little bit longer for this feature to be funded in the open source version.

This talk from a Twilio developer illustrates the usefulness of direct feedback for documentation.