Update desktop file with useful defaults. So it is ready to use by maintainers without further modification (but renaming).
Updated. But what does this file do? It does not go into distribution, does it?
Desktop files are used by Desktop Environments to expose installed programs to the end user. I guess they can be compared to "Start Menu" entries on Windows. So it is only to be used when installing Simutrans system-wide.
But I think no script includes this file right now. If so, it needs to be inside the simutrans, or not?
No.