Remove DocFX from repo

[ashovlin]

Description

1. Removes the DocFX executable and assemblies from the repository, in favor of using a local one on development and/or build systems
2. Regenerated docs using the same docfx version. This appears to pick up:
   1. New operations on the client from the SDK dependency
   2. Renamed assembly (which I think dates back to the original launch

Testing

Clicked around docs in a browser via a local web-server, didn't notice any obvious regressions

Screenshots (if appropriate)

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• [X] My code follows the code style of this project
• [ ] My change requires a change to the documentation
• [X] I have updated the documentation accordingly
• [X] I have read the README document
• [ ] I have added tests to cover my changes
• [ ] All new and existing tests passed

License

• [X] I confirm that this pull request can be released under the Apache 2 license