Additions to metrics documentations

[jschintz]

Describe the feature

Docs for metrics currently omits some useful fields. 'Label', 'type' & 'sql'

Describe alternatives you've considered

Using the manifest/catalogue file instead is an option to rebuild the docs.

Who will this benefit?

Consumers of metrics looking at documentation

Are you interested in contributing this feature?

Since I pay for dbt cloud, I'd prefer dbt to.

[antaradas94]

I also look forward to this feature. I had implemented metrics , but the dbt docs dont really display the type, label etc. i think it would be amazing if the dbt docs also had this feature to display more parameters.