Fix ServiceTypes, ExcludeServiceTypes, and DocPath desktop file entries to match XDG specifications

src/knetstats.desktop

@@ -29,4 +29,4 @@ Terminal=false
 Type=Application
 Categories=Qt;TDE;Network;
 X-TDE-StartupNotify=true
-DocPath=knetstats/index.html
+X-DocPath=knetstats/index.html