Adds an ink annotation: freehand strokes, each through its points with round caps and joins; its rectangle is fitted to them.
public PdfInkAnnotation AddInkAnnotation(IReadOnlyList<IReadOnlyList<PathPoint>> strokes, PdfAnnotationOptions? options = null)
One or more strokes, each of one or more points in default user space.
Colour, width, flags and markup texts; null for one-point red strokes.
ISO 32000-2 §12.5.6.13, Table 185 (PDF 1.3).