U turn support

[GiantWod]

Which area of IMT is your request about? (ex: Lines, Fillers, UI)

Describe your idea clearly and concisely.

A way to mark u-turns using IMT, possibly a u-turn mode and a straight line mode with a button to switch between them

Screenshots?

Provide a visual if possible what your idea would look like

Why would this idea be a good addition to IMT?

Add any other context or screenshots about the feature request here. U-turns are kinda common and afaik there is no way to mark them

[Tysseract]

this is a duplicate of https://github.com/MacSergey/NodeMarkup/issues/296