Create homepage for Relays

[chakany]

Pledge
17k sats (may change)

Is your feature request related to a problem? Please describe.
In the future, relays are going to become much bigger than they are now, and not only relay owners but also people in general are going to want a easy way to:

1. Find the operating costs of the relays (estimate)
2. Make a donation
3. See who operates it
   There will also be premium relays too, but I understand that's already in the works (this could be an extension of that)

Describe the solution you'd like
I would like the index page of relays to display such information as described above. Instead of telling the user to connect with a client, it would show the information on a webpage.

Describe alternatives you've considered
There could be metadata that would be served (similar to what we have currently with operator pubkey and email info and such) to clients and they can display that information.

[ralyodio]

you should just provide a ./public folder for the http version and we can put whatever we want in there.