Remove the link to Snap

[R3dst0ne]

Since having an outdated official Snap package (Neither stable nor nightly are up-to-date) is in no way beneficial.
I propose removing the links to it until this gets fixed.

As soon as it gets updated to the current version (3.8.0), I will add the links again.

If this PR gets accepted, I will create another one for the develop branch.

[MarcinOrlowski]

I'd remove the banner from master only as we want them fixed not removed anyway. But instead of spending time on removing the banner you might want to take a look at builder scripts to see maybe you will see what the issue is there?

[maehne]

I agree with @R3dst0ne to remove link from master, but not from develop. However, we need to be sure, once the Snap package is fixed that the README contains the link again after merging develop into master.

[R3dst0ne]

Sadly, I do not have any experience with Snap's or configuring build processes. So fixing this has to be done by someone else.
@MarcinOrlowski maybe you as the creator of the Snap and @anrouxel as the creator of the unofficial one can work together to fix this.

After short reconsideration, I agree that the banner and link should stay in the README on develop.

@BFH-ktt1 what is your opinion on this topic?
Is something stopping you from merging this PR?