Enable programlisting output that links to actual documentation

[svenevs]

Currently, the programlisting is just transformed into a raw .. code-block::. This is better than nothing, but

1. Explicitly parsing the programlisting for a given refid is easy (and already partially implemented).
2. Figuring out how to write the output is the hard part.
   • Pygments is already setup for Sphinx, need to resolve generating links and highlighting the code.
   • Make sure users set primary_domain in conf.py.
   • Allow extension mappings to sphinx lexers (yet another config variable).

Ideally it would be similar to the Python viewcode extension, but it will be a challenge. This one is quite far off in the future.

[2bndy5]

hopefully, the resolution could also be used to address

(!) Unabridged API: unexpected kind 'example' (IGNORED)

I'm mainly posting this to subscribe to this issue 😉