Roman Bogorodskiy authored Nov 13, 2021 and Sébastien Wilmet committed Feb 28, 2024

Wrapped help message strings are missing spaces which results
in joined words, e.g.:

--html-dir HTML_DIR   The directory where gtk-doc generated
documentation isinstalled.

Note the "isinstalled" which should be "is installed".

Fix by adding missing spaces.

!68