Review, Fix & Document Joplin dev-env use-cases

This is kind of a personal "fallen behind" / "ignored" tech deck issue that would be nice to clear up for me ("bob"). It's something I've run into often as I've been away form Joplin and come back to find some missing / forgotten changes that take some time to clear up before I can get back to developing again.

As of this point, any Joplin issues I've worked on, I've only been able to run with fixture data, or starting with empty data locally.

I'm not currently able to run locally with...
- Staging data
- Production data

I think it might be a good time to take the time to research all the use-cases and document it in our "alpha-documentation" and update the readme if needed.

We do have this all documented, but I'm experiencing some additional issues that probably stem from recent changes and inconsistencies with our .env files that maybe missing some important info.

Honestly, I won't the reasons until I tinker with and get help.