Enable tagging of sources, not just models

[mferryRV]

Describe the feature

Allow tagging of sources, similar to tagging of models.

Describe alternatives you've considered

The primary use case for tagging in sources as well as models is to isolate a set of transformations soup-to-nuts. When I do a bunch of work on, say, email data, I want to show people the sources, transformations, and outputs I created. I can do that for one source with DAG commands like source:braze_segment+

But what about when I add Responsys? Mandrill? Now I have multiple sources and I can't display them all at once. I'd need to pick a downstream table and show all the upstream dependencies, but what if some of my source tables aren't being used yet?

It would be easier if I could just tag source tables as related to my models & display this full process for my teammates to understand the work I've done.

Additional context

This use case is primarily aimed at dbt docs functionality, so changes in the flexibility of the Lineage Graph might make this less necessary.

Who will this benefit?

Anyone trying to onboard someone to a new dataset would benefit from the ability to show everything at their disposal.

[drewbanin]

Yep! Great idea - let's do it :)

There are a couple of semi-related issues here that i think we should consider here too:

• Feature: Configurable, arbitrary key in schema.yml to enhance documentation #1362
• Add CLI option to exclude specific schema/custom tests #1586

[mferryRV]

Stoked to see this prioritised!

For the curious users seeking a stop gap, you can highlight multiple sections of the docs Lineage Graph by putting a space between the commands, e.g. source:my_source_1+ source:my_source_2+ like so:

Not quite as flexible as tagging, but still useful!

[beckjake]

This is fixed in #2039