fix: add optional type annotation to github source for pyright adherence

[cmpadden]

Tell us what you do here

The following changes were required for the Github source to have proper adherence to our company pyright / ruff policies. Thought I'd push upstream in case others require similar tweaks when bringing this source into their project.

• Adds Optional types to nullable function parameters
• Adds period to end of docstring sentences

Loving these verified sources! 🙏