Add some strip length gotchas to Help

[OakCityDirtyRandy]

Some of the oddest things you'll notice on a group ride -- riding behind other VESC riders -- are weird Taillight behaviors that are often the result of misspecified strip lengths. This is especially common in daisy-chained configurations, because what you expect to see in one strip will bleed into another. This edit seeks to clarify why this happens.

[OakCityDirtyRandy]

This is the revised text for the strip length help.

Note:

Strip length can be determined by counting the number of physical LEDs in the strip.
Incorrectly specified strip length will often manifest itself in animations behaving oddly.
Strip length is especially important in configurations in which the strips are daisy-chained together, which the LCM will treat as though it is a single strip.
In daisy-chained configurations, incorrect strip lengths result in animations split over multiple strips and they just don't look right.
Strip length is uniquely important for the Status bar, as it provides information on remaining charge, which might be presented incorrectly if the count is wrong.

[lukash]

An unwanted merge commit in this PR branch as well.