Content changes from Nuritzi

To reflect the ways EndlessOS has diverged from GNOME

[endlessm/eos-shell#3909]
Simple grammar fix

[endlessm/eos-shell#2316]
Updated translation source file per recent changes

[endlessm/eos-shell#2316]
Merge pull request #3 from endlessm/shell/2316

Content changes from Nuritzi