Help menu link to manual file

Hi,

I would like the Help menu to link with the manual for fast check/search.

Thanks

The link could lead to the https://prepomax.fs.um.si/documentation/ site since new version of the manual is uploaded with each release of PrePoMax.

The manual is less than 1 Mb. I would include it in the installation folder to be available offline.

Currently, the manual is updated some time after the release of a new version of PrePoMax but it may change and then it could be added to the package with PrePoMax build. For now, a link to the aforementioned site with documentation (where also other files and versions are available) seems to be a good idea.