Add documentation for new Community Profile Report indicator

[nmdefries]

Summary

Document CPR indicator with hospital admissions signal.

[capnrefsmmat]

Should this page explicitly address how this data is different from our hhs and hospital-admissions sources? We now have three sources with hospital-related data and I don't know if users will be able to distinguish them. (For instance, I'm out of the loop, so I don't know how this is different from the HHS signals we already publish.)

Also, do we not have prop signals for this source?

[krivard]

Draft of clarifications requested by @capnrefsmmat

Includes reference to results from Maria's analysis, which we may want to make available publicly. @mariajahja or @ryantibs , any corrections or objections?

[nmdefries]

We are not adding prop signals at this time.

[ryantibs]

I would remove the reference to the statement that a copy of the analysis is available. Otherwise, I think it's fine to refer specifically what we found (comparing HHS to CPR).

No prop signals: that will be problematic, because we're intending to show this on the COVIDcast dashboard (for county-level hospital admissions), and we will need prop signals for that.

[capnrefsmmat]

The documentation seems clear enough (except one comment on license), modulo Ryan's concerns