chore: Adds GH action to trigger generate_llmstxt.py, testing action

[J2-D2-3PO]

Description

Spawned off of #3045. The goal of this PR is to add a GH action to trigger docs/scripts/generate_llmstxt.py created in #3045 and serve as a testing branch for the new action.

What this PR does:

• Add .github/workflows/generate-llms.yaml to trigger docs/scripts/generate_llmstxt.py
• In pyproject.toml, add new entry llmspy = ["PyYAML>=6.0"] in [project.optional-dependencies] for use by hatch in creating env to run script
• Updates docs/scripts/generate_llmstxt.py with logic to get right directory before calling script
• Removes llms.txt and llms.md so we can test
• Makes some sort of change to this branch to check that llms.py is properly triggered
• Update action logic to work in prod i.e. [on.push.branches]

Testing

• Locally:
  • In shell, python3 scripts/generate_llmstxt.py -> runs script and generates expected folders in static dir
• On branch:
  • Initial commits with GH action + deleted llms.txt and llms.py
  • Make any change to the branch and confirm action triggered
  • Confirm that, upon action triggered, expected files generated

[circle-job-mirror]

Preview this PR with FeatureBee: https://beta.wandb.ai/?betaVersion=1d1a1c2fe19899c71a378e043857290820a94afd

[J2-D2-3PO]

@scottire this is about 99% ready to go. Commit history is a little confusing, because I was fumbling around with testing for a bit.

Anyways, confirmed that the llms.txt was autogenerated and pushed to this test branch in d39df34.

So I think the remaining todo here is to update the action logic so that it pushes to main. LMk if you think we should add other logic here.

Once that's done, I was thinking we could just squash and merge into your #3045. LMK if that works