Quickstart Fixes

[kmad]

This PR fixes two minor issues and adds a quickstart script to get things up and running without modification.

Specifically the following included changes got to working code:

• Added null checks to rlm/core/rlm.py
• Swapped dotenv for python-dotenv as a dependency
• Adds quickstart.py which is simply the example from the README as a file a user can invoke after cloning the repo

[alexzhang13]

@kmad I generally like these changes, but I do have an example already called rlm_example.py. Can you merge this example into your quickstart.py (I like this name better anyways).

Can you also remove the uv.lock changes? I will edit the uv.lock myself after merging, most of the diffs in there are redundant atm.

Also, feel free to point to this file in the README somewhere in the quick setup section. Thanks!

[kmad]

This is complete. I also ran into a minor, periodic bug where the logging would fail due to the model parameter not being a string, which has also been corrected.

I switched the quickstart example to use openai instead of portkey since I figure more folks will have immediate access to the former, but I left mention of portkey in the comments. Let me know if any other changes.

[alexzhang13]

Cool thank you! Also yeah, Portkey was a legacy thing because I was given Portkey credits for my experiments haha, I think changing to OAI is better. Thanks!