Draft: Resolve "enh(doc): missing manual pages for applications and executables"

Description

This requires pandoc to be installed first

Closes #918

How to test it?

The manpages are intended to be used when sight is installed on the system, for instance for the Debian package.

However you can test that the page are well generated using the command:

man -l sightviewer.1

Data

(Links to the needed data)

Some results

(Some interesting results, screenshots, perfs, ...)

Additional tests/tasks to run

(If you need some specific tests/tasks...)

• Additional test 1
• ...