Update changelog for 0.3.1
Update changelog for 0.3.1

scalameta/scalafmt,Daxten/scalafmt,scalameta/scalafmt,Daxten/scalafmt,olafurpg/scalafmt,olafurpg/scalafmt,scalameta/scalafmt,olafurpg/scalafmt,scalameta/scalafmt,olafurpg/scalafmt