release: update NEWS

NEWS

+=======================================================
+network-manager-applet-1.8.12
+Overview of changes since network-manager-applet-1.8.10
+=======================================================
+
+* Allow creation of PPPeE connection without a parent interface.
+* Add an option to set a connection as Metered.
+* Make the form layout consistent with GNOME UI style.
+* Convert editor into a GtkApplication with an app menu.
+* Fix a potential crash in the certificate picker with no modules.
+* Fix build warnings with GCC 8.
+* Support building against Ayatana AppIndicator.
+* Updated Brazilian Portuguese, Croatian, Czech, Danish, Dutch, Esperanto,
+  French, German, Icelandic, Indonesian, Italian, Latvian, Lithuanian,
+  Polish, Russian, Serbian and Spanish translations.
+
 ======================================================
 network-manager-applet-1.8.10
 Overview of changes since network-manager-applet-1.8.8