The easiest way to provide translations is to download full sources from the git repository and then edit the translations using qt linguist.
Otherwise you should consider to use other applications like lokalize or poedit.
Download the stable sources or checkout the git master, do whatever you want and then ask for upstream integration using the "pull requests" tool.
I spend as much of my spare time as possible working on YaFlight, YaInstall and thus YaLib and any donation is appreciated.
Donations play a crucial role in supporting Free and Open Source Software projects. So why are donations important?
As a developer the more donations I receive the more time I can invest in working on Ya*. Donations help cover the cost of hardware for development and to pay hosting bills.
This is critical to the development of free software.
As a developer I greatly appreciate any donation you can make to help support further development of the Ya* tools.