Version 2.0.0-beta.1

Version 2.0.0 is intended to improve DocumentService's API names and reduce clutter.

Beta 1 so far includes @pythonpluh's pull request which renames methods to comply with the "Async" suffix standard.

The PR also differentiates IsOpenAvailable and IsOpen some more.

Version 2.0.0 will also likely remove hooks and look at other API improvements based on developer experiences, however will not largely change the mechanics behind how DocumentService works. So it should be a fairly straightforward upgrade.

(This beta is not available on wally)