`mkdocs` works with markdown similar to `mdbook` but is generally more
pleasing to the eye and has several nice UX features.
This PR does the bulk of the transition - likely, a followup would be
needed to fully make use of the extra features and navigation.
Book pages have been kept url-compatible, meaning that for the most
part, old links should continue to work!
Co-authored-by: Etan Kissling <etan@status.im>
Jacek Sieka