More colour on coursier

CONTRIBUTING.md

@@ -24,13 +24,14 @@ Contents:
 
 Getting started
 =======
-Scala js dom currently targets java 17 for maximum compatibility. 
+Scala js dom currently targets java 17 for maximum compatibility. If your shell is targeting a JVM higher than 17, you may experience confusing error messages when starting SBT.
+
+[Coursier](https://get-coursier.io/) is the de facto standard for artefact fetching in scala. Using coursier it is possible to launch SBT with a specific JVM version. The default [installation](https://get-coursier.io/docs/cli-installation) of coursier will put `cs` on your path, after which the following command (run in the root of the project)
 
 ```sh
 cs launch sbt --jvm 17
 ```
-Would start sbt on a jvm that is known to work with the project
-
+will (if necessary download and) start sbt with temurin 17 - i.e. a jvm known to be compatible with the project.
 
 Packages
 ========