Sync exposed CodeFormatterOptions with currently supported cli options

[Phault]

Tried to incorporate your feedback. Personally think it's just fine to have an enum with just two values, so I went along with it. Had to make EndOfLine public as well, hence I also moved it out of PrinterOptions.cs, but wasn't sure where to place it.

Not familiar with how that PublicAPI.Unshipped.txt stuff works, but I let my IDE update it. Let me know if it's all wrong :)