* 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
* RPM/DEB for systemd-based systems
Similar to https://github.com/status-im/nimbus-eth2/pull/2691, this PR
introduces packaging for nimbus beacon node.
Instead of relying on interactive prompts, a default configuration is
included that connects to mainnet and expects there to be an execution
client running with websockets enabled on the same host, on the standard
websocket port.
Should the user need to configure their nimbus after installation (for
example with a different web3 url), the "standard" way of doing so via
`systemctl` edit is recommended.