Merge branch 'rel-v12' into 'master'

Document changes and release v12

See merge request Librem5/librem5-base!110

debian/changelog

+librem5-base (12) amber-phone; urgency=medium
+
+  [ Adrien Plazas ]
+  * gnome-notfit-all: Drop evince
+  * gnome-all: Add evince
+
+  [ Guido Günther ]
+  * base: Install apparmor
+
+  [ Angus Ainslie ]
+  * alsaucm: set some defaults
+
+ -- Angus Ainslie <angus@akkea.ca>  Tue, 17 Dec 2019 09:04:28 -0800
+
 librem5-base (11) amber-phone; urgency=medium
 
   [ Adrien Plazas ]