Setup dbt-checkpoint in the repo

[dcaribou]

See what dbt-checkpoint is about here.

Relates to #205.

Problem → this works, when pre-commit runs it does so using the project root as its current directory, which has the effect that

• we have to update paths to data in dbt to be relative to the project root
• dbt artifacts are generated in the root instead of in the dbt subfolder

this is not ideal.

Update: check https://docs.sqlfmt.com/integrations/trunk as an option to deal with linters at module (sub-folder) level.