more information about public rooms

[tooomm]

Copied over from old repo: arxanas/drafts.ninja#40

Public rooms miss some information:

• Format not named. It's called Format, but actually there are just used packs listed
  better go with Draft (EMN/EMN/SOI), Sealed (EMN/EMN/SOI/EMN/EMN/SOI), Chaos Draft, ..?
• no room age / creation time

Also Seats sounds a bit weird to me. Would Players be a better term? (I'm not a native speaker!)