Change auto-formatting settings

[japgolly]

Once our PR queue is cleared, on the 2.x branch lets:

• Add import normalisation and sorting to auto-formatting (I use it everywhere and it's GLORIOUS)
• I wouldn't mind increasing the column width from 79 to 120
• Format ScalaDoc in a more concise way - it takes up so much vertical space atm
• Force use of override
• sort members
• More?

[armanbilge]

Yes PLEASE! Formatting for build.sbt as well.

[japgolly]

I think we're good enough. I don't see a rule for the other features (and I'm not gonna write myself this time) so I'll just close this hey