Polish codes

[Radonirinaunimi]

Toward addressing #326 $-$ which would be good to have prior to releasing the stable v1 version.

CAPI TODO:

• Update the documentation of the CAPI; I think we can rip out most of the documentation and instead refer the main documentation. I don't see a point in replicating the documentation in two places and we should only document differences of the CAPI to the Rust module
• Document the naming scheme for the CAPI, which is pineappl_[struct]_[method]
• Document the stability guarantees: we never remove functions, only add or deprecate them. This is important, because many Monte Carlo generators depend on the CAPI and they usually get updated only if things break; and we don't want to break them

[felixhekhorn]

maybe consider involving @ramonpeter ? since documentation is usually a good onboarding task

[Radonirinaunimi]

maybe consider involving @ramonpeter ? since documentation is usually a good on-boarding task

That is a very good idea!

[ramonpeter]

Not quite sure what, but just contact me for more details

[Radonirinaunimi]

@ramonpeter, the main idea would be to add documentation where TODO's appear (and optionally improve the codes where there are also TODO's).