[cleanup] Add package description

[dominikschulz]

This commit adds package descriptions to the generated Deb and RPM packages to make them easier to discover and separate from other similar packages.

Fixes #2695

[fetwar]

This PR looks good, the only thing I worry about is the difference between short and long descriptions, I can't really seem to find how goreleaser handles the two and I think the short description should be the primary goal to update. Viewing the long description often requires a flag like apt search's --full option.

I couldn't find much documentation around specifying two different descriptions, but looking at short descriptions vs long in issue #2695 it seems to be that at least apt just truncates after the top line.

Do you think it may be best to write the descriptions so that the top line is suitable for a short summary and the remainder is suitable for long summary?

The slightly more awesome standard unix password manager for teams.

... rest of your long description.

Another option would be to rewrite a short description for the packages, but I think the current description on github is great.

Maybe something like this for gopass

gopass password manager - full featured CLI replacement for pass, designed for teams.

... rest of your long description.

[AnomalRoil]

LGTM

[dominikschulz]

@fetwar Thank you, fixed.