added desktop entry and did some changes on package. Also added icon

[fosforizo]

No description provided.

[TolisSth]

In general we prefer normal branch names, keep that in mind for future PRs. Also please do provide descriptions.

Also, there are several problems with this PR, namely:

• The icon does not show, probably because of the size being too big, so you should resize to something smaller in the power of 2 and in the area of 256x256.
• There are problems with rights, UniNews creates a lot of folders therefore when installing that's a big problem because it installs with user rights but it lives in a place (/usr/bin/) that requires more rights. Therefore I suggest finding a solution.