added explanation how to use this repo

README.md

+# ALP4 repository template
+
+Use this template for the course ALP4.
+
+## How To
+
+* fork this repository
+* add teaching assistant (TA) and your peers to this repository. 
+* give TA reporter role and your peers maintainer (or developer)
+* for every exercise, checkout either the *c-example* or the *java-example*
+  branch and name the new branch accordingly
+
+## Submission
+
+In Whiteboard, add the corresponding commit hash in the comment field of the
+exercise. 
+
+Keep in mind this is specific to the course in Summer 2022! 
+
+## Contributions
+
+Feel free to open issues or submit merge requests for changes. Also you could
+fork this to prepare templates for other courses.