[calls] metainfo: Update description

[Evangelos Ribeiro Tzaras <devrtz src gnome org>]

commit dd22510516b7520fd3c37e5f99a29d0b91dc8c49
Author: Evangelos Ribeiro Tzaras <devrtz fortysixandtwo eu>
Date:   Tue Oct 19 19:39:31 2021 +0200

    metainfo: Update description

 data/org.gnome.Calls.metainfo.xml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/data/org.gnome.Calls.metainfo.xml b/data/org.gnome.Calls.metainfo.xml
index 11c956a8..01158ea7 100644
--- a/data/org.gnome.Calls.metainfo.xml
+++ b/data/org.gnome.Calls.metainfo.xml
@@ -7,7 +7,9 @@
     <summary>Make phone and SIP calls</summary>
     
     <description>
-        <p>Calls is a simple, elegant phone dialer and call handler built using GTK+ 3.</p>
+      <p>Calls is a simple, elegant phone dialer and call handler for GNOME.
+      It can be used with a cellular modem for plain old telephone
+      calls as well as VoIP calls using the SIP protocol.</p>
     </description>
 
     <url type="homepage">https://gitlab.gnome.org/GNOME/calls</url>