Update README.md

Added a few lines to the getting started experience.  Will add a few others around the Mac experience once I get this building

README.md

@@ -70,6 +70,8 @@ At the moment is has the following features:
         * `xcode-select --install`
 * Install GraalVM (minimum RC10)
 * Set `GRAALVM_HOME` to your GraalVM Home directory e.g. `/opt/graalvm` on Linux or `/Users/emmanuel/JDK/GraalVM/Contents/Home` on macOS
+* `git clone https://github.com/jbossas/protean-shamrock.git`
+* `cd protean-shamrock`
 * `mvn install`
 
 The default build will create two different native images, which is quite time consuming. You can skip this