New review comment by sgn on void-packages repository

https://github.com/void-linux/void-packages/pull/29342#discussion_r600079761

Comment:
`docs` subdir is about building gtk-doc, which is meant for developer and requires `gir`.
Normal users want man instead.
I couldn't build the gtk-doc on my _single_ try, so I disabled it. No code, no problem :-p