* update docs
* introduce mdbook-admonish for nice looking callouts
* new section on data directory
* recommend source build for advanced users and direct the rest to
binaries
* more strongly highlight that execution client is needed
* write an actual deposit guide
* remove cruft / fix links / etc
* systemd: use same service file as package
* systemd: recommend setting up a user
* clean up obsolete / ephemeral notes
* eth1 -> execution, in many places
* clean up docker instructions to match the experience of running the
runner script
* add basic instructions / links for execution clients other than geth
* clear a few more references to JSON-RPC, update to REST
* update hardware requirements with execution client extras
* start talking about merge requirements (this needs a dedicated page)
* note that binaries do exist, where relevant
* list gitcoin under donations
* update syncing docs
* `NOT` is for `NOTICE` in logs
* update rpi hardware recommendations
* prevent automatic doppelganger restarts in systemd service file
* cp
* rename API to JSON-RPC API
* rename api to json-rpc api, add rest api page
* remove extra emacs generated file
* remove extra emacs generated file
