feat(scripts): make toggle-keyboard-backlights more robust

private_dot_local/scripts/executable_toggle-keyboard-backlights.sh

@@ -8,8 +8,16 @@ PREVIOUS_SETTING=$(< $KEYBOARD_PATH)
 if [[ $PREVIOUS_SETTING -eq $OFF ]]
 then
   echo $ON > $KEYBOARD_PATH
+  if [[ $? -ne 0 ]]; then
+    echo "ERROR: Could Not Update Settings"
+    exit 1
+  fi
   echo "Keyboard Backlighting: ON"
 else
   echo $OFF > $KEYBOARD_PATH
+  if [[ $? -ne 0 ]]; then
+    echo "ERROR: Could Not Update Settings"
+    exit 1
+  fi
   echo "Keyboard Backlighting: OFF"
 fi