Improve cross-linking of types in 'Pandoc Lua Filters' docs

[0xdevalias]

In the spirit of:

• https://pandoc.org/CONTRIBUTING.html

  • Write or improve documentation. If you ran into a problem which took more time to figure out than expected, please consider to save other users from the same experience. People writing the documentation tend to lack an outside view, so please help provide one. Good documentation is both difficult and extremely important.

Describe your proposed improvement and the problem it solves.

In the Lua Filters documentation, there are generally 2 different sections for the various types, and their constructors. eg.

• Emph (type)`: https://pandoc.org/lua-filters.html#type-emph
• Emph (contructor): https://pandoc.org/lua-filters.html#pandoc.Emph
• CodeBlock (type): https://pandoc.org/lua-filters.html#type-codeblock
• CodeBlock (constructor): https://pandoc.org/lua-filters.html#pandoc.CodeBlock

A pattern I've noticed is that the 'type' usually includes a cross-link to the 'constructor':

Values of this type can be created with the pandoc.Emph constructor.

Values of this type can be created with the pandoc.CodeBlock constructor.

But the 'constructor' doesn't seem to include a crosslink to the 'type', and usually only refers to the more generic Block / Inline:

Returns:

• new object (Inline)

Returns:

• CodeBlock element (Block)

While I was recently exploring writing a lua filter I found myself spending a lot of time jumping back and forth in the docs, and felt like it would be easier if those sections cross-linked to one another.

Describe alternatives you've considered.

I'm aware of this issue/PR, but the nuance is different:

• Restructure Lua and JSON filter docs #8750
  • Simplify and reorganize Lua filter introduction #9106

This docs issue is also unrelated, except for improving the docs UX for new users in general:

• Improve pandoc.scaffolding section in 'Pandoc Lua Filters' docs (RE: Custom Writers) #10531

[jgm]

@tarleb what do you think?