[release-notes/gnome-3-28] Add missing screenshots to Makefile

[Piotr Drąg <piotrdrag src gnome org>]

commit ee6952064893c48045964c92d27fe7909d963407
Author: Piotr Drąg <piotrdrag gmail com>
Date:   Tue Mar 6 16:22:33 2018 +0100

    Add missing screenshots to Makefile

 help/Makefile.am |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/help/Makefile.am b/help/Makefile.am
index 8dafce2..9b4558e 100644
--- a/help/Makefile.am
+++ b/help/Makefile.am
@@ -12,11 +12,13 @@ HELP_MEDIA = \
  figures/boxes-os-downloads.png \
  figures/builder.png \
  figures/calendar-month-view.png \
+ figures/cantarell.png \
  figures/files-starred.png \
  figures/flatpak.png \
  figures/osk.png \
  figures/photos-import.png \
  figures/placeholder.png \
+ figures/thunderbolt.png \
  figures/usage-performance.png
 
 HELP_LINGUAS = cs de el es fr fur gl hu it ja ko lt pl pt_BR ro sv tr