Given a project directory `my-project` which projectile correctly identifies because it is a git project.

Inside `my-project` there is a `my-module` directory. It is a git submodule and therefor projectile identifies it as a project of it's own.

But I want all files inside of `my-project/my-module` to be considered as part of `my-project`.

What is the idiomatic way to configure this?