@joellabes: In our case, we want to store large configurations as code within our dbt project. The configs contain metadata about our project, our database, and much more, which come in very handy to dynamically generate stuff in models, tests, macros, etc.
We currently store those configs in a macro (see related thread here), but it would be very nice to be able to store them in a YAML file instead (it would at least provide better IDE support to edit the file).
What would be even better is if dbt provided a way to store custom configs directly within the project itself, perhaps as a custom_conf key in dbt_project.yml. But currently that returns an error:
Runtime Error
at path []: Additional properties are not allowed ('custom_conf' was unexpected)