Restore numbering for TOC, add TOC to keyCommands

[seanbudd]

Link to issue number:

Fixes #16059
Closes #16106

Summary of the issue:

Due to markdown limitations, numbered headings and a numbered table of contents was removed from the user and dev guide when migrating from t2t to markdown.
However, these can be restored with CSS.

Description of user facing changes

Restores numbered headings to the table of contents and the headings within the user guide and developer guide.

Added TOC to key commands guide. Numbered heading are avoided as they don't match the user guide and may be misleading.

Description of development approach

Testing strategy:

Generated docs and compared to 2023.3 documentation for english and arabic.
Compared dev guide, changes, key commands and the user guide.

Known issues with pull request:

None

Code Review Checklist:

• Documentation:
  • Change log entry
  • User Documentation
  • Developer / Technical Documentation
  • Context sensitive help for GUI changes
• Testing:
  • Unit tests
  • System (end to end) tests
  • Manual testing
• UX of all users considered:
  • Speech
  • Braille
  • Low Vision
  • Different web browsers
  • Localization in other languages / culture than English
• API is compatible with existing add-ons.
• Security precautions taken.

[AppVeyorBot]

• Build (for testing PR): https://ci.appveyor.com/api/buildjobs/w7ebhas06jnt3vok/artifacts/output/
• CI timing (mins):
  INIT 0.0,
  INSTALL_START 1.0,
  INSTALL_END 0.9,
  BUILD_START 0.0,
  FINISH_END 23.7

See test results for failed build of commit 7f27720d43

[michaelDCurran]

Assuming this works okay with rtl, then this looks okay to me.
One thing just to note though is that in comparison with the 2023.3 user guide, the numbers in the table of contents now appear in place of the bullets, rather than inside the links. I don't necessarily have an issue with this, but just pointing it out.

[seanbudd]

@michaelDCurran - I've fixed RTL languages for the TOC, unfortunately there is unexpected behaviour for arabic-indic numbers when using counters for automatic nested/recursive counters, so we have to define our own manual nesting for each level

[seanbudd]

One thing just to note though is that in comparison with the 2023.3 user guide, the numbers in the table of contents now appear in place of the bullets, rather than inside the links.

This could easily be fixed if it's a better idea. I might run it by quentin as there is a visual difference, I find keeping it out of the link tag visually nicer but it's definitely a preference thing

[AppVeyorBot]

• PASS: Translation comments check.
• PASS: Unit tests.
• PASS: Lint check.
• FAIL: System tests (tags: installer NVDA). See test results for more information.
• Build (for testing PR): https://ci.appveyor.com/api/buildjobs/owqq4oxihd6wl2vp/artifacts/output/nvda_snapshot_pr16226-31213,3e8de111.exe
• CI timing (mins):
  INIT 0.0,
  INSTALL_START 1.0,
  INSTALL_END 0.9,
  BUILD_START 0.0,
  BUILD_END 30.0,
  TESTSETUP_START 0.0,
  TESTSETUP_END 0.3,
  TEST_START 0.0,
  TEST_END 2.4,
  FINISH_END 0.2

See test results for failed build of commit 3e8de111e5