* reorganise navigation menus
* update light client guide with comparison table
* add suggested fee recipient and JWT secrets to the merge guide
* add some background info to book readme
* add JWT docs
also limit toc to make it displayable with substeps.
* Use final `v1` version for light client protocols
* Unhide LC data collection options
* Default enable LC data serving
* rm unneeded import
* Connect to EL on startup
* Add docs for LC based EL sync
`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>