Add docs to methods

[gonzalocasas]

Autocomplete is great, but it would be amazing if the documentation of the .NET methods could be added to the stubs as well.

[ZacZhangzhuo]

agree. if there are more prompts of multiple constructors and descriptions that would be great. simply add more comments in each definition. This will help us A LOT to code faster and know Rhino Geometry better! @sbaer @BobMcNeel