Add kata to demonstrate submodules and subtree are used in combination

As developers, we would like to work in a flat repository when committing code to my component/framework including functional test and resources, but I cannot share the whole repository.
As a consumer/product we do not want to merge in changes from the framework to our git history. We just want to add the "component/framework" as a dependency to my product.

Create a kata to demonstrate and practice this scenario