Doc: Developer reference update

[rdrll]

Description

Major update on the Black classes and the Black exceptions page in the Developer reference.

They now matched with the current code base.

• All Classes under src/black are now documented
  • Created two secondary title under the top level Black classes: Black classes (for non-Enum classes) and Enum classes to improve architectural clarity. (Previously the Enum class in the rst file was wrote as a parallel top level title yet it's actually a subsection under the top level title Black class)
• All exceptions are now documented
• Modified a few docstrings in src/black/handle_ipynb_magics.py and src/black/trans.py to conform to the rst syntax (enforced by Sphinx).
  • The docstrings were modified to resolve two types of errors that would raise by Sphinx when rendering the rst files with the original docstrings: Block quote ends without a blank line; unexpected unindent. and Bullet list ends without a blank line; unexpected unindent. .
  • These docstrings were not issue before because these Classes were not documented previously, so it won't fetched and examined by Sphinx.
• Modified the note on the Developer reference main page.
  • It's now stating that only the Black functions part is outdated, while others have been updated to the latest version.

Please let me know if any changes are needed!

Checklist - did you ...

• Add an entry in CHANGES.md if necessary?
• Add / update tests if necessary? not necessary
• Add new / update outdated documentation?

[github-actions]

diff-shades reports zero changes comparing this PR (0b83f53) to main (63481bb).

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What is this? | Workflow run | diff-shades documentation

[JelleZijlstra]

Thanks!

I'm not sure though how useful this "Developer Reference" is. I never look at it, and inevitably it's going to go out of date again.