Provide example code in repo / docs

[adammw]

Is your feature request related to a problem? Please describe.
Trying to understand how to use the SafeHandle code to call methods and unsure if what I'm seeing is a bug in the generation logic or working with types I just don't understand yet. More specifically, trying to follow the guide of "Using the Low-Level Monitor Configuration Functions", and unsure how to work with Handles, SPAN<>, Optional Arguments, Null Pointers, etc.

Describe the solution you'd like
A directory of sample code for various common win32 APIs, showing how to use the SafeHandle and Span<> APIs.

Describe alternatives you've considered
Current I have to google around (usually finding resources refering to older P/Invoke APIs), or look at the tests which aren't exactly clear.