Add CONTRIBUTING.md

CONTRIBUTING.md

@@ -0,0 +1,13 @@
+# Contributing guide
+
+## Adding new features
+
+If you want to add a new feature, check if it's already been discussed in the issues list.
+
+Before you start working on an existing feature / bugfix, let us know you're taking it on in its comments :)
+
+## Adding a new Scala version
+
+1. Add it to `./scala-versions` (one version per line)
+2. Run `sbt generateAll`
+3. Commit and open a pull request.

README.md

@@ -81,15 +81,7 @@ If you need a different `toString`, we suggest that you implement one yourself.
 
 ## Contributing
 
-If you want to add a new feature, check if it's already been discussed in the issues list.
-
-Before you start working on an existing feature / bugfix, let us know you're taking it on in its comments :)
-
-To add a new Scala version:
-
-1. Add it to `./scala-versions`
-2. Run `sbt generateAll`
-3. Commit and open a pull request.
+See [CONTRIBUTING.md](./CONTRIBUTING.md)
 
 ## Maintainers