gtk-doc: update to 1.32.

GTK-Doc 1.32  (Aug 15 2019)
===============

Hotfix release.

GTK-Doc 1.31  (Aug 5 2019)
===============

Nonmaintainer release to fix "Wrong permissions for style CSS file" (#84)

GTK-Doc 1.30  (May 08 2019)
===============

GTK-Doc is now using python-pygments to do the syntax highlighing. It is not
depending on highligh or source-highligh anymore.

This version ships with a new expermiental gtkdoc-mkhtml2 toolchain replacing
gktdoc-mkhtml+gtkdoc-fixxref.

(wiz)