Better documentation & easier way to set up sync for a project

[paravoid]

(First off, the doc.md instructions are outdated, still pointing at pdb_sync, which is deprecated since v1.0.0.)

Moving the sync code to the peeringdb CLI to provide a more loose coupling is understandable. However, AIUI, this puts downstream users in the odd position of having to set up peeringdb CLI configuration (using e.g. peeringdb config set), with the exact same database and API username/password information as their project, run the sync, then have the (downstream) Django code also use the same database almost separately. Have I misunderstood how this is supposed to work?

It'd be neat if there was a better integration between the two projects. That is, for example, if there was a way for the pdb_sync management command to be restored, but make it a simple proxy to "peeringdb sync", while also giving the ability to use the configuration (settings.py) from one's project, including the database configuration. Would something like that make sense?