Update Roslyn Insertion Tool docs

[dmonroym]

The https://github.com/dotnet/roslyn-tools/blob/main/src/RoslynInsertionTool/README.md is severely in need of an update.

Some options no longer exist and several other new ones aren't there. Perhaps it would also be a good time to use the full names instead of abbreviations as things like bn, ac, and qv are not intuitive.