docs(observability): Add advanced configuration, authentication, and telemetry collection docs

[schnecle]

• Pull advanced configuration options into a use case based general page
• Pull common authentication steps into a general page
• Pull descriptions of collected metrics into a common observability page and add in sections for traces and logs
• Remove duplicated sections from Google Cloud and Firebase plugins and reference the general observability docs

Checklist (if applicable):

• PR title is following https://www.conventionalcommits.org/en/v1.0.0/
• Tested (manually, unit tested, etc.)
• Docs updated (updated docs or a docs bug required)

[MichaelDoyle]

Nice! I made a bunch of nit picky grammatical tweaks you can take or leave.

A few broad callouts I want to make, though:

1. I think we need to decide when and where we refer to "telemetry plugin" and when we refer to "genkit monitoring". Especially since we are doing double-duty with the plugin, wrt "firebase" and "google cloud".

2. In some ways, we are doing a bit of a round-a-bout by pointing the Google Cloud docs to the Firebase instructions (whereas before it was the opposite). It's much improved, no doubt.

   • One thing we talked about that could potentially help is making "includeable" snippets that can go into all 3 docs ("Observing AI workflows, Firebase Plugin, Cloud Plugin).