Provide extension documents in AsciiDoc format

[SaschaWillems]

As the spec itself is missing some key Vulkan related extensions, people still need to refer to the text files for extensions instead of being able to browse and search them via the docs site.

Would it be possible to convert the extension documents into AsciiDoc? Or at least move to to AsciiDoc for newer extension documents.

That way we could easily integrated the files into the docs site, similar to the Vulkan extension proposals.

[oddhack]

Questions:

• Are we just talking about ext/GL_EXT_vulkan_glsl_relaxed.txt and khr/GL_KHR_vulkan_glsl.txt? There are a lot of GLSL extensions. 46 of the 95 total files under extensions/ at least mention Vulkan in some fashion.
• Assuming we're talking about more than just those two:
  • Do we need to convert all extensions including vendor and ext, or just khr?
  • Do we even need to convert them? We can include the plaintext files in Antora with trivial asciidoc markup. Yes, the will be ugly, but that would be doable much faster than asciidoc markup conversion.
  • Do they need to be (or even should be) a separate Antora component, or just tagged onto the end of the GLSL spec component as pseudo-appendices(*)? It's not a big deal either way.

(*) I say "pseudo-" because Antora does not have any notion of "chapters" or "appendices", it just assembles the individual pages it's given and uses the navigation index provided by the repository.