Please help test-drive the new WebThings documentation

Who fancies doing some proof-reading of documentation?

I’ve written a long-overdue new user guide for WebThings using Mkdocs https://github.com/WebThingsIO/docs/pull/31

Rendered version here: https://benfrancis.github.io/webthings-docs/

Feedback and inline suggestions on the GitHub pull request would be gratefully received!