The supermodule should only contain the submodules + the script to put them all together.

If it contains more than the submodules + the script (+ the readme) to put them all together, then its more than a supermodule i.e. there is a difference in building all libraries separately, and building the supermodule.

This is bad naming. If more is being done, we should consider renaming it. If not, we should reduce it to the submodules + a script for conciseness.