API Documentation with Sphinx

[adamamer20]

This PR adds a simple API documentation built with sphinx and automatically deployed with GH Action.
I had to use a custom GH Action to deploy general docs (mkdocs) and API docs (sphinx) at the same time.
I also had to create a custom decorator to "inherit" class docstrings in the case of multiple inheritance (like GridPandas, AgentSetPandas, ...).

The GH Action is set to be deployed on every push to this branch. I will update to 'main' when merged.
You can preview the look of API docs with the current PR here: https://adamamer20.github.io/mesa-frames/api/index.html

This PR depends on #74

[codecov]

Codecov Report

Attention: Patch coverage is 94.11765% with 1 line in your changes missing coverage. Please review.

Files	Patch %	Lines
mesa_frames/utils.py	87.50%	1 Missing ⚠️

Files	Coverage Δ
mesa_frames/abstract/agents.py	89.21% <ø> (ø)
mesa_frames/concrete/agents.py	95.56% <ø> (ø)
mesa_frames/concrete/model.py	75.86% <ø> (ø)
mesa_frames/concrete/pandas/agentset.py	88.34% <100.00%> (+0.10%)	⬆️
mesa_frames/concrete/pandas/mixin.py	86.91% <ø> (ø)
mesa_frames/concrete/pandas/space.py	100.00% <100.00%> (ø)
mesa_frames/concrete/polars/agentset.py	86.15% <100.00%> (+0.10%)	⬆️
mesa_frames/concrete/polars/mixin.py	96.05% <ø> (ø)
mesa_frames/concrete/polars/space.py	98.75% <100.00%> (+0.03%)	⬆️
mesa_frames/utils.py	87.50% <87.50%> (ø)