Adding some build information to readme

README.md

@@ -4,4 +4,16 @@ Main service for the BFH AppTrans exercise.
 
 Live demo (with mock external systems) at https://bfh-pcws-mock.herokuapp.com/swagger-ui.html
 
-See https://github.com/SamuelBucheliZ/bfh-apptrans-exercise/blob/master/README.md
+See also https://github.com/SamuelBucheliZ/bfh-apptrans-exercise/blob/master/README.md
+
+## How to build
+
+Build war for Tomcat deployment (for the exercise)
+```
+mvn clean package -Pwar
+``` 
+
+Build standalone jar (for demo and Heroku)
+```
+mvn clean package -Pjar
+```