Tweak HowTo instructions, for 0.1.0 release

Author: dwijnand

README.md

@@ -1,20 +1,49 @@
-# CAUTIONS!
-Current released Scalafix supports ExplicitNonNullaryApply [ONLY in Scala 2.12](https://github.com/scala/scala-rewrites/issues/31). 
-Scalafix will support 2.13 and 2.11 with cross-building ExplicitNonNullaryApply rule against them.  
-
 # Scalafix Rewrites for Scala
 
-## To develop a rewrite
+## How to run the rewrites
+
+Add the `sbt-scalafix` sbt plugin, with the SemanticDB compiler plugin enabled ([official docs][1]):
 
+```scala
+// project/plugins.sbt
+addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.9.17")
 ```
-sbt ~tests/test
-# edit rewrites/src/main/scala/...
+
+```scala
+// build.sbt
+inThisBuild(List(
+  semanticdbEnabled := true,
+  semanticdbOptions += "-P:semanticdb:synthetics:on", // make sure to add this
+  semanticdbVersion := scalafixSemanticdb.revision,
+))
 ```
 
-## To run the rewrites
+Then run the desired rewrite(s) ([official docs][2]), in sbt:
+
+```scala
+> scalafix dependency:fix.scala213.ExplicitNonNullaryApply@org.scala-lang:scala-rewrites:0.1.0`
+> Test/scalafix dependency:fix.scala213.ExplicitNonNullaryApply@org.scala-lang:scala-rewrites:0.1.0
+```
+
+You can also add the following to your `build.sbt`:
+
+```scala
+ThisBuild / scalafixDependencies += "org.scala-lang" %% "scala-rewrites" % "0.1.0"
+```
 
-1. [Install Scalafix](https://scalacenter.github.io/scalafix/docs/users/installation.html)
-2. Enable synthetics in SemanticDB; e.g. `semanticdbOptions += "-P:semanticdb:synthetics:on"` in sbt 1.3+
-3. Run the [external rule](https://scalacenter.github.io/scalafix/docs/rules/external-rules.html), e.g.:
-  * `scalafix dependency:ExplicitNonNullaryApply@org.scala-lang:scala-rewrites:VERSION`
-  * `Test/scalafix dependency:ExplicitNonNullaryApply@org.scala-lang:scala-rewrites:VERSION`
+and then:
+
+```scala
+> scalafix fix.scala213.ExplicitNonNullaryApply
+> Test/scalafix fix.scala213.ExplicitNonNullaryApply
+```
+
+[1]: https://scalacenter.github.io/scalafix/docs/users/installation.html
+[2]: https://scalacenter.github.io/scalafix/docs/rules/external-rules.html
+
+## To develop/contribute to any of the rewrites
+
+```
+sbt ~tests/test
+# edit rewrites/src/main/scala/...
+```