add logging about relay status

Currently logs only consist of status of messages, like this:

`... msg="http: POST /eth/v1/builder/validators 200" duration=1.155462 method=POST path=/eth/v1/builder/validators status=200 version=v1.6`

And eventually there are some logs about errors:

`... msg="error calling registerValidator on relay" error="Post \"https://bloxroute.max-profit.blxrbdn.com/eth/v1/builder/validators\": context deadline exceeded (Client.Timeout exceeded while awaiting headers)" method=registerValidator numRegistrations=2 ...`

What does that mean? is it a temporary error? should I be concerned?

So, it would be great to have logs about the actual status of relays. For example lighthouse consensus client says this:
`Connected to beacon node(s) synced: 1, available: 1, total: 1, service: notifier`

Would it be possible to add a line every now and then that says the total number of relays, how many are connected, how many have problems, etc? It is important to give users a reassurance that everything is working ok.