Create proof of concept that the napari sphinx theme doesn't need to be maintained separatedly

[willingc]

References and relevant issues

This PR is a proof of concept.

Description

Motivation

Maintaining a custom theme adds complexity and maintenance burden. Ideally, one would opt for a custom theme
only if a major feature could not be implemented by another well maintained theme.

Currently, our docs workflow and contribution is more complex than needed if someone is trying to do a local documenation build.

Proof of Concept

This PR demonstrates the possibilities:

• moving from napari sphinx theme to stock pydata sphinx theme
• move templates from napari sphinx theme to docs directory _templates
• move napari css from napari sphinx theme to docs directory _static
• combine custom.css with the napari css to have one file
• add annotation/comments for the conf.py file to better understand the configuration
• fixes the copybutton
• added more precommit checks
• added logging for scripts

Next steps

This is by no means merge ready. It was basically to prove to myself that we could create a napari styled theme using the pydata sphinx theme and remove the need to maintain a separate repo for the napari-sphinx-theme.

This all works locally on my mac. Let's see if this draft can pass our CI.

[psobolewskiPhD]

Wow! Thanks for the effort on this one!

I'm of two minds about this.
On one hand having it all in one place is really convenient!
On the other hand, the idea of our own theme was to make it easier to use by other repos, e.g. napari-animation (which does use it for docs).

Also I noticed prettier in the pre-commit: does it support myst markdown and the colon fencing we use?
It's something we ran into in the past when trying to implement formatting, see some discussion here:
#54 (comment)

[willingc]

@psobolewskiPhD This really was a proof of concept (wasn't aware of napari-animation). I think that the benefit of this PR will be to simplify the napari sphinx theme. Doing the proof of concept, I removed a bunch of cruft and added some best practices. Happy to do it in the napari sphinx theme repo.

[jni]

😂

[willingc]

Closing as this is a proof of concept, and I'm satisfied with the results.