StrokeCap
type StrokeCap = 'none' | 'round' | 'square' | 'arrow-lines' | 'arrow-equilateral'
The possible values are:
'none': nothing is added to the end of the stroke'round': a semi-circle is added to the end of the stroke'square': a square is added to the end of the stroke'arrow-lines': an arrow made up of two lines is added to the end of the stroke