mod_translation_updater.py: Add content title and description to template

[rubenwardy]

Problem

As a content creator, I want mod/game titles and descriptions to be translated

Solution

As part of the extraction process, the mod_translation_updater.py script should also title and description from .conf into the template. It should probably read .conf for a textdomain if present

Additional context

https://api.minetest.net/translations/#translating-content-meta

[rubenwardy]

cc @Wuzzy2

[rollerozxa]

For the new .po translation format that we will likely primarily use the Gettext tools for, a script that will generate dummy gettext calls based on the content conf file that can then get populated by xgettext sounds like a ok idea, or if we have a wrapper script for generating and updating Minetest content translations using Gettext tools that does this in the background.