Dockerize graphql package externals services

[belgamo]

Summary

The goal is to make easier for the new contributors the setup of this project and decrease the need to create externals accounts like AWS which requires a credit card.

Changelog

• Added a docker-compose file in GraphQL package
• Updated contribution guide
• Updated env vars config files to replace them when using docker

[petruspierre]

Great job 🚀

[petruspierre]

I think it's valid to investigate if Android will have trouble finding the bucket data, now that it's on localhost.
For example, profile pictures may not appear in the android app.