Add documentation build script, fix build warning, and update docs on building docs

[mfisher87]

Description

Local builds were failing because of a warning thrown by autodoc because jupytergis_lab was not installed, so GISDocument couldn't be found by autodoc. Edited environment-docs.yml to support this.

Also, the documentation documentation (:smile:) was suggesting using make, when we don't have a Makefile. I added a script instead and updated the docs correspondingly.

Checklist

• PR has a descriptive title and content.
• PR description contains references to any issues the PR resolves, e.g. Resolves #XXX.
• PR has one of the labels: documentation, bug, enhancement, feature, maintenance
• Checks are passing.
  Failing lint checks can be resolved with:
  • pre-commit run --all-files
  • jlpm run lint

---

📚 Documentation preview: https://jupytergis--584.org.readthedocs.build/en/584/
💡 JupyterLite preview: https://jupytergis--584.org.readthedocs.build/en/584/lite

[github-actions]

👈 Launch a Binder on branch mfisher87/jupytergis/local-docs-build

[mfisher87]

Looks like I broke RTD build, returning to draft

warning  libmamba You are using 'pip' as an additional package manager.
    Be aware that packages installed with 'pip' are managed independently from 'conda-forge' channel.
Installing pip packages: ../python/jupytergis_lab
  error: subprocess-exited-with-error
  
  × Preparing metadata (pyproject.toml) did not run successfully.

[github-actions]

Integration tests report: appsharing.space

[mfisher87]

Figured it out. Can specify the Python modules as dependencies in environment-docs.yml but they also depend on the javascript packages. So our build needs to do the jlpm build steps before creating the docs environment. Then the docs environment can be created in one step. The local build also requires this. I updated the docs accordingly!

#585 to try and make the python packages' dependencies more self-contained.

[mfisher87]

Would like to hear your feedback @YaoTingYao ! I don't like that this makes our instructions a bit more complicated, but I think the best course is to accept that until we can figure out how to make our Python package builds more self-contained (#585)

[martinRenou]

Thanks!