Can I add Lightdash metrics to my dbt docs?

Yes! Gary James from BeautyPie wrote an excellent guide on this: Generating a Table for Your Lightdash Metrics in dbt.

A dbt macro uploads all your Lightdash metrics and metadata to a dbt model. You can then explore this data catalog directly in Lightdash.

The macro iterates through your dbt graph object to pull all the relevant information automatically.