Added a simple readme

readme.md

+# Simple mpi sanity tests 
+
+The idea is to use these tests to assure mpi functionality on a basic level on container/ software rebuild
+
+* CI agents have to run somewhere on /lustre/....
+* I suggest creating a subdir in rz for the build system
+* each ci run should create its own subdir in that directory by using uuidgen or using the uuid of the CI pipeline-/step hash
+