Add German trannslation (#1033 by @HeyMyian)

CREDITS.md

@@ -15,6 +15,7 @@ The default language is English (UK) with English (US) as an option.
 
 * Dutch: Martijn van der Kleijn (@mvdkleijn)
 * French: Jan Lüdke (@jyhelle)
+* German: Myian (@heymyian)
 * Latin American Spanish: Tommy Marplatt (@tmarplatt)
 * Norwegian: Veronica Berglyd Olsen (@vkbo)
 * Portuguese: Bruno Meneguello (@bkmeneguello)

novelwriter/dialogs/about.py

@@ -180,6 +180,7 @@ class GuiAbout(QDialog):
         aboutMsg += "<h4>{0}</h4><p>{1}</p>".format(
             self.tr("Translations"),
             self._wrapTable([
+                ("Deutsch", "Myian"),
                 ("English", "Veronica Berglyd Olsen"),
                 ("Español Latinoamericano", "Tommy Marplatt"),
                 ("Français", "Jan Lüdke (jyhelle)"),