add readme to testapp

test_app/README.md

@@ -0,0 +1,8 @@
+Test App for integration testing purposes.
+
+```../bin/embark run``` to check if everything is behaving as expected
+
+```../bin/embark test``` to see tests are working as expected
+
+```dist/index.html``` and ```dist/test.html``` to check different functionality
+