Is your feature request related to a problem? Please describe.
DBT introduced model contracts in 1.5.

The constraints field has a way of setting up foreign keys as part of the contract. I don't see a way to use this feature in the dbterd documentation. My models are too big for the relationships tests to run.

Describe the solution you'd like
Supporting inferring relationships from DBT model contract native constraints.

If already possible, specifying so in the documentation would be great.

Describe alternatives you've considered
I can use the Snowflake dbt_constraints package, but I'd rather use the native DBT constraints feature if that's available. Also dbt_constraints functionality of creating Snowflake constraints is compatible with native model contracts so that's another reason I'd write the native code instead.

I could also use dbt_utils.relationships_where but I'm not sure how (maybe it's possible with the algorithm selection command line syntax?)

I can help writing the code (really like this project!), but want to make sure there's not something I'm missing first. Thanks!