Removing doc options and stop installing documentation

[jperkin]

Some packages have a doc option that enables building and installing the bundled documentation, and some packages just install the documentation regardless and have mandatory dependencies on things like docbook.

I've long thought it's well past the time that this is in any way useful. 20 years ago when you may have been inside a data centre with only console access or in a remote location with no other access to the internet, sure, having the documentation installed on the system may occasionally have been useful.

In 2025 when you are almost guaranteed to at least have a mobile device with Internet connectivity that you can use to browse the online documentation and more? Seems unlikely.

It's not just the extra dependency requirements. Some of the installed documentation is huge, includes images, etc. Most of it is HTML which then means you then need to install some browser to make it useful. Some systems are still limited by disk space.

I propose we just stop installing things under share/doc unless they are small pieces of useful information in a plain README or similar.

We should also remove doc options. Either the documentation is small and useful, in which case we should install it, or it's not and we shouldn't. doc options usually just end up broken because nobody tests them in non-default configurations.

Of course we should continue to provide man pages, info pages, examples, etc.

[alarixnia]

anything depending on doxygen unconditionally can probably just be deleted. :-)