Updae to scala 3

scala/README.md

@@ -1,3 +1,22 @@
-# Gilded Rose starting position in Scala
+# Gilded Rose starting position in Scala 3 scalatest
 
-TODO: explain how to run this code
+
+## Build the project
+
+``` cmd
+sbt compile
+```
+
+## Run the Gilded Rose Command-Line program
+
+For e.g. 10 days:
+
+``` cmd
+sbt "run 10"
+```
+
+## Run all the unit tests
+
+``` cmd
+sbt test
+```