Initial Sphinx documentation setup with autodoc support

[PES2UG23CS205]

Summary

This PR introduces an initial proof-of-concept for a structured documentation system for Neural-LAM using Sphinx.

What’s included

• Basic Sphinx documentation setup inside the docs/ directory
• Autodoc configuration to automatically generate API documentation from existing docstrings
• Mocking of heavy ML dependencies so documentation can build without requiring the full ML environment
• Initial API reference page integrated into the documentation index

Motivation

Issue #61 discusses setting up a structured documentation system similar to PyTorch Geometric, combining tutorials and automatically generated API references.
This PR provides a minimal starting point that the community can iterate on and extend.

How to build locally

From the docs directory:
python -m sphinx -M html source build

Further improvements such as theme customization, tutorials, and CI integration can be added in follow-up PRs.

[PES2UG23CS205]

Hi! I realized after opening this PR that it would have been better to discuss the approach on the issue first.

I created this as a small proof-of-concept while exploring Issue #61 to better understand the codebase and the documentation needs. I’m very happy to adapt the approach or close the PR if you’d prefer to discuss the direction first.

I’d really appreciate any feedback on whether this setup aligns with what you had in mind for the documentation system.

[joeloskarsson]

Hi! Making a proof-of-concept like this is great, and as you write it's probably good to discuss over the exact approach a bit. But you can mark the PR as a draft PR, to keep it around for reference. No need to completely close it.

Maybe you can share a bit in #61 the motivation for the specific approach i this PoC? This can then be part of the project proposal.

[sadamov]

there are already two PRs in place for this issue: #272 and #252 ... closing this draft to preserve time