Add bindings for clipboard management with (new, improved) bmo-clip

dotfiles/i3/config

 bindsym $mod+Home           exec "$spn bmo menu home"
 bindsym $mod+Shift+Home     exec "thunar"
 
+bindsym $mod+Insert         exec "$spn bmo clip save"
+bindsym $mod+Shift+Insert   exec "$spn bmo clip open"
+
 bindsym $mod+m              exec "$spn bmo menu status"
 bindsym $mod+Shift+m        exec "i3-dmenu-desktop --dmenu='bmo dmenu'"
 bindsym $mod+o              exec "$spn bmo menu context"