docs: duplicate autogenerated heading ids (`_api`, `_lua`)

[e-kwsm]

https://neovim.io/doc/user/deprecated/ Generated at 2026-05-06 15:25 from 27e7aba

TOC at right is rendered as

• Deprecated Features
  • Deprecated in 0.13
  • Api
  • Events
  • Lua
  • Deprecated in 0.12
  • Api
  • Diagnostics
  • Highlights

I would like to suggest structuring like

• Deprecated Features
  • Deprecated in 0.13
    • Api
    • Events
    • Lua
  • Deprecated in 0.12
    • Api
    • Diagnostics
    • Highlights

Plus, all the API headings in versions from 0.8− to 0.13 have id of _api, therefore "Api" under e.g. "Deprecated in 0.10" navigates to that in 0.13.

[yochem]

I think it's the same structure in the help file and would thus require changes there (e.g. changing the header API to API ~ column heading.

[justinmk]

a mitigation is simply to not auto-generate a heading if one already exists. although, it would be the same amount of work to just append a number (_lua-1, _lua-2).