[CT-2810] [CT-2775] [Feature] Show contracts in project's dbt docs site

[sambloom92]

Is this your first time submitting a feature request?

• I have read the expectations for open source contributors
• I have searched the existing issues, and I could not find an existing issue for this feature
• I am requesting a straightforward extension of existing dbt functionality, rather than a Big Idea better suited to a discussion

Describe the feature

With the recent introduction of model contracts, I've noticed that the dbt docs website produced by dbt docs generate does not seem to include any information on contracts at all (unless I'm not looking in the right place?). A lot of the constraints that previously would have been implemented as tests would have been visible in the project docs website, but if they are implemented as contracts they are not visible anymore, so this could arguably be considered a regression.

Describe alternatives you've considered

Users can always refer to the project's source code for contract information, but I don't see any reason why this information wouldn't be included in the project's docs website

Who will this benefit?

Anyone using contracts in their projects, who want their model contracts to be well documented.

Are you interested in contributing this feature?

No

Anything else?

No response

[jtcohen6]

@sambloom92 Thanks for opening — it's a totally fair & legitimate request.

Let's see if we can make some small tweaks to the dbt-docs site to accommodate model contracts:

• Lower lift: For a model with an enforced contract, say as much somewhere on that model's page
• Slightly bigger lift: Represent constraints (U, PK, FK, C) on columns, similar to how they're currently represented for generic tests

I'm going to transfer this one over to the dbt-docs repo, since that's where the code changes will need to happen