Adds a polyline annotation: the open path through vertices; its rectangle is fitted to them.
public PdfPolyLineAnnotation AddPolyLineAnnotation(IReadOnlyList<PathPoint> vertices, PdfAnnotationOptions? options = null)
At least two vertices in default user space.
Colour, width, flags and markup texts; null for a one-point red line.
ISO 32000-2 §12.5.6.9, Table 181 (PDF 1.5).