Don't bind ports by default, instead suggest binding ports in local `docker-compose.override.yml`

[sergiofenoll]

Currently the identifier and triplestore's ports are bound in docker-compose.dev.yml. Although having a default port as soon as you create a new project (or clone a project based off the template) is helpful, I have found it annoying when needing to run multiple stacks at once. I'd suggest that instead of binding these by default, the committed docker-compose files should have no bound ports and instead the README should explain how to add them to docker-compose.override.yml.

As an example from Kaleidos, sometimes it is necessary to run multiple stacks side-by-side (Kaleidos, Themis, and Valvas, to test the document release chain). Each of these stacks defaults to binding their identifier and triplestore to the same ports. If I need to run them side-by-side I need to edit their docker-compose(.dev).yml files to change the port bindings and ensure that I don't accidentally commit my changes. If the port bindings were defined locally in the respective override files, I wouldn't have to keep track of this.