Update 'Test App'

Test-App.md

@@ -0,0 +1,8 @@
+This is **Test** Application
+
+It is a hello world c program that require gcc to build and using Makefile to manage.
+Recent drone ci/cd is added to the system. So this Test App also being use for testing the CI/CD too.
+
+How to build and run:
+- make
+- ./hello