Review and update the Jamulus.1 manpage documentation

I don't think we have a step in the release process to ensure the Jamulus.1 manual page documentation is up to date.

That could probably do with adding.

Ideally, we'd also have translated version of the Jamulus.1 manpage available to install, too.

There _should_ be a lot of overlap between the manpage and the website and wiki. They should be kept aligned. The manpage needs reviewing because I think it's likely been left adrift and could do with an update.

Start by locating the Jamulus.1 manpage and reviewing the related website and wiki content for alignment. Check how the release process handles documentation, then define completion as an updated manpage, a documented release step, and a clear decision on translated versions being available to install.

Written by the indexing model from the issue text.