Add Email address of artists

src/picplanner-application.c

@@ -128,7 +128,7 @@ picplanner_application_show_about (GSimpleAction *action,
   GtkWindow *window = NULL;
   const gchar *authors[] = {"Zwarf <zwarf@mail.de>", NULL};
   const gchar *artists[] = {"Zwarf <zwarf@mail.de>",
-                            "Rajdeep Singha", NULL};
+                            "Rajdeep Singha <rajdeepsingha@proton.me>", NULL};
   const gchar *copyright =
   "Copyright \xC2\xA9 2020 Zwarf\n\n"
   "License Map Data ODBL OpenStreetMap Contributors\nMap Imagery CC-BY-SA 2.0 OpenStreetMap";