Move beamline layout configurations to here, and rename repository to something PCDS-specific

[ZLLentz]

Configuration of which lcls happi beamlines lead up to which hutch are defined in lightpath here: https://github.com/pcdshub/lightpath/blob/master/lightpath/config.py. But eventually lightpath should become facility-agnostic, so these should move to a pcds repo.

[klauer]

What about making device_config a Python package?

If it's importable, we can configure happi easily. We could also add further structural information (beamlines, paths, what have you>)

[hhslepicka]

👍 on making device_config a package!

[ZLLentz]

I like this idea, we may want to consider renaming it to pcds_device_config or pcds_config or ecs_config or lcls_config or something along those lines