Restrict generate sources to output yml files only

[kon-mal]

Is your feature request related to a problem? Please describe.
Generating full .yml files (model name, list of columns, empty description fields) for every model in a dbt project - thorough documentation.

Describe the solution you'd like
If the current generate sources function had a flag that disables .sql files creation / or yml-only flag, it would achieve exactly that. Although it's set up for sources specifically, if you provide your analytics schema in the .dbt_coves.yml, it will create the yml definitions for all of the dbt models in a project.

Describe alternatives you've considered
As an alternative I had a wrapper python function that captured terminal output of this function https://github.com/dbt-labs/dbt-codegen/blob/0.3.2/macros/generate_model_yaml.sql for each model and created the ymls.

Additional context
The generate sources function is extremely useful in creating staging models for a dbt project. It seems, however, that it could be easily extended to help with thorough documentation of all models within a dbt project. Ideally, it wouldn't then put the "sources" part at the top of the file, but that's much easier to get rid of than creating all of the ymls from scratch!

[ssassi]

Nice idea @kon-mal.
I would suggest then creating another variant of the generate subcommand, i.e. dbt-coves generate properties.
Instead of reading the DB schema, I'd suggest reading models information from the dbt manifest.
The tool could list the models so the user selects which ones to generate.

[noel]

@kon-mal generate properties now exists