Expand Headlights On help for greater clarity

[OakCityDirtyRandy]

As with PR #107 , there is plenty of information in the help for Headlights On but additional clarification on some points could help people understand the relationship between LEDs and Headlights/Taillights. As with LEDs On, Headlights On is best understood as the default state when the board is started. For runtime, it's a little more complex and that's explained.

[OakCityDirtyRandy]

Below is the text in an easier to read format than settings.xml. The objective is to clarify that Headlights On requires LEDs On (or Lights On, if using the buttons in Refloat.)

Sets the default state for Headlights and Taillights when the board is started.

Headlights and Taillights activate when you engage the board (use Headlights Transition to set activation behavior).
Which are Headlights and Taillights is determined by direction of travel, not the physical front and rear of the board.
LEDs must be on through the LEDs On menu option or the Lights button in Refloat in order for the Headlights menu option or Refloat Headlights button to turn on Headlights and Taillights.
Headlights and Taillights can be toggled at runtime from the Refloat Headlights On/Off button or via a footpad konami code:
LEFT LEFT RIGHT: Turn Headlights on
RIGHT RIGHT LEFT: Turn Headlights off
After the Headlights are toggled this way, this option no longer affects the Headlights state until the board is restarted.