Support Hierarchical Tags

Is your feature request related to a problem?

There is growing support in the OAS community for the idea of hierarchical tags (see OAI/OpenAPI-Specification#1367). The current consensus is that UIs like SwaggerUI can implement this with no change required in the OAS, and that this would be a much appreciated feature. I would like to implement it in SwaggerUI and would like help identifying the best way to do so.

Describe the solution you’d like

Tags such as Petstore|Mammals|Dogs should render as

## Petstore

### Mammals

#### Dogs

....

EDIT: Temporary Solution

I’ve implemented and published a package for this. Instructions for use are here. There is also a PR out for this (here), but it is long stale and I doubt that Swagger will ever take interest in it. For now, your best bet is to use my published package, which works well as an ES module include in a webpack scenario OR as a global module via unpkg.

[mathis-m]

At least in the APIs I work with, this could still be very long. It’d be nice to have some kind of vertical gray line on the left to signify how deeply something is nested.

How about:

[kael-shipman]

Thanks for commenting! Good to know others find this desirable.

To the devs: I repeat my offer to implement this and PR it if you’ll give me a push to start me in the right direction 😉.