[Chore] Clean Up XML Comments for V10

[iancooper]

Is your feature request related to a problem? Please describe.
Our style is to document public members of classes and public interfaces with XML comments /// Those comments produce Intellisense.

Describe the solution you'd like
Provide clear help to users of our APIs on how to use them successfully. Some notes on fixes:

• Summary should summarize expected behavior
• Remarks should indicate notes to maintainers or users
• Params and Return values should use to indicate types where appropriate

We should avoid just repeating the name, and provide more helpful hints

Describe alternatives you've considered
The alternative is not to document, but Intellisense remains helpful