added another layer between the power button press and the keyboard script, with option to override using a hook

scripts/core/sxmo_powerbutton.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env sh
+
+# include common definitions
+# shellcheck source=scripts/core/sxmo_common.sh
+. "$(dirname "$0")/sxmo_common.sh"
+
+if [ -x "$XDG_CONFIG_HOME/sxmo/hooks/powerbutton" ]; then
+	"$XDG_CONFIG_HOME/sxmo/hooks/powerbutton" "$@"
+else
+	sxmo_keyboard.sh "$@"
+fi