[iagno] Add F1 shortcut for opening help.

[Arnaud B. <arnaudb src gnome org>]

commit 76759bf8982c7c6bffb5d8363e1a00fa03029807
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Mon Jan 7 18:30:21 2019 +0100

    Add F1 shortcut for opening help.

 src/iagno.vala | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/iagno.vala b/src/iagno.vala
index 732860b..1becef8 100644
--- a/src/iagno.vala
+++ b/src/iagno.vala
@@ -195,6 +195,7 @@ public class Iagno : Gtk.Application
         set_accels_for_action ("win.redo",              { "<Shift><Primary>z"       });
         set_accels_for_action ("win.back",              {                 "Escape"  });
         set_accels_for_action ("win.toggle-hamburger",  {                 "F10"     });
+        set_accels_for_action ("app.help",              {                 "F1"      });
         add_action (settings.create_action ("sound"));
         add_action (settings.create_action ("color"));
         add_action (settings.create_action ("num-players"));