[DOCS] Salt Reference Docs: Sphinx Theme Refresh (Furo, Sphinx Book, or Alternative Third-Party Managed Theme) and Deprecation of saltstack2 custom theme

[ScriptAutomate]

Description

The saltstack2 Sphinx theme is fairly out-dated and in need of updates and better maintainership if wanting to continue to be used over time.

Suggested Fix

Salt Project should migrate to a new theme that is maintained by a larger community, such as Furo (which is currently used by Salt Install Guide, Salt User Guide, and many official Python projects throughout the Python community), or Sphinx Book Theme (which is maintained by ExecutableBooks, and may have missing features and expanded support that furo doesn't currently have).

If looking to Sphinx Book, should look at migrating the docs using Furo also over to the same theme, for a unified experience.

Type of documentation

Salt Project reference docs

Location or format of documentation

Source of reference docs theme in this repo:

• doc/_themes/saltstack2

The published reference docs are found here:

• https://docs.saltproject.io/en/latest/contents.html

The other published docs using furo can be found here:

• Salt Install Guide: https://docs.saltproject.io/salt/install-guide/en/latest/
• Salt User Guide: https://docs.saltproject.io/salt/user-guide/en/latest/