https://scalacenter.github.io/scalafix/docs/rules/external-rules.html
project/scalafix.sbt
addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.9.19")
sbt shell
> scalafixEnable
> scalafix dependency:[email protected]:replace-symbol-literals-to-string:0.1.1
> test:scalafix dependency:[email protected]:replace-symbol-literals-to-string:0.1.1