[calls] metainfo: Add "launchable" tag

[Evangelos Ribeiro Tzaras <devrtz src gnome org>]

commit a0208c7119f4fce3b80a66e1fa52ebb4e59c56de
Author: Evangelos Ribeiro Tzaras <devrtz fortysixandtwo eu>
Date:   Tue Oct 19 19:44:02 2021 +0200

    metainfo: Add "launchable" tag
    
    See
    https://www.freedesktop.org/software/appstream/docs/chap-Metadata.html#tag-launchable

 data/org.gnome.Calls.metainfo.xml | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/data/org.gnome.Calls.metainfo.xml b/data/org.gnome.Calls.metainfo.xml
index 80c55348..229c3acc 100644
--- a/data/org.gnome.Calls.metainfo.xml
+++ b/data/org.gnome.Calls.metainfo.xml
@@ -16,6 +16,7 @@
     <url type="bugtracker">https://gitlab.gnome.org/GNOME/calls/issues</url>
     
     <project_group>GNOME</project_group>
+    <launchable type="desktop-id">org.gnome.Calls.desktop</launchable>
 
     <screenshots>
       <screenshot type="default">