Does `PolygonVisibility.py` handle cases where the observer is on an edge or vertex?

[VEFrenovator]

Hello, @AyushBhandariNITK,

I’m currently working on an Art Gallery Theorem animation solution using Manim, and I’ve encountered several issues with calculating the visibility polygon.

All the implementations I’ve seen so far do not work correctly when the observer is placed on an edge or a vertex. Since this is crucial for the Art Gallery Theorem, my question is: Does PolygonVisibility.py handle cases where the observer is on an edge or vertex?

P.S. It would be great if you could add a LICENSE.md file (e.g., MIT license) to the repository.