Update documentation to mention fruits of iquery probe

[mlissner]

Now that the iprobe daemon is finally up and running, we should document it. I imagine this will make sense in our coverage page and our alerting page. We won't want to mention iquery or anything technical like that, but we'll want to just say that we get the name and basic data from all new cases within XX minutes of when they're in PACER, and that alerts can go out immediately after that.