libgnt/libgnt

Add an option to disable building the docs
release-2.x.y
2021-09-25, Helmut Grohne
2374624f79fe
Add an option to disable building the docs

Testing Done:
Built with the option on and off.

Bugs closed: LIBGNT-17

Reviewed at https://reviews.imfreedom.org/r/945/
syntax: regexp
^build(.+)?\/
^obj-.+\/
packaging\/debian\/.+\.substvars$
packaging\/debian\/.debhelper\/
packaging\/debian\/debhelper-build-stamp$
packaging\/debian\/files$
packaging\/debian\/libgnt.+\/
packaging\/debian\/tmp\/