feat: Add documentation build and versioning workflow

[Riddhimaan-Senapati]

Description

This PR introduces a new GitHub Actions workflow that automates the process of building and versioning the project documentation on gh-pages. The workflow triggers on published releases, builds the docs using Sphinx and the existing Makefile, updates the latest documentation, and automatically manages the versions.json files for the version switcher, ensuring that the docs site always reflects the latest and previous major/minor releases. This solves #153

@dskarbrevik Can you review this PR? Let me know if you need anything else.

Contributor License Agreement

• confirm you have signed the LangFair CLA

Tests

• no new tests required
• new tests added
• existing tests adjusted

Documentation

• no documentation changes needed
• README updated
• API docs added or updated
• example notebook added or updated

Screenshots

[dylanbouchard]

@dskarbrevik can you please review?

[dylanbouchard]

@doyajii1 any interest in reviewing this PR?

[doyajii1]

@Riddhimaan-Senapati Thank you for supporting the LangFair to have automated docsite build. This is very essential for the LangFair. Two things might be good to tested/addressed:

1. Can you try to build this on your forked repo to test the output together? Also this will give us little more understanding why the version dropdown menu isn't working at our current LangFair docsite.

2. We should be tracking v0.# on our releases for docsite. For example, we should track docsite LangFair version start from 0.3 to 0.6 such as the version selector drop down menu should have list of v0.3, v0.4, v0.5, v0.6. I believe it might need some level of python script to just extract v0.# version tags and replace versions.json file around "Update versions.json files" step.

Forgive me for checking so late at this, I will stay more tuned to give back feedback faster.