tagGroups functionality

[timmyGr]

Redocly has an x-tagGroups extension. https://redocly.com/docs-legacy/api-reference-docs/specification-extensions/x-tag-groups

example:

x-tagGroups:
  - name: Records
    tags:
      - Record
      - Record Applicant
      - Record Guests
      - Record Locations
      - Record Form
      - Record Attachments

So the user would see the sidebar item "Records", expand that, then see the following tags, and then expand those to see the endpoints. We have a massive amount of routes and functionality similar to this would clean up the UI immensely.

Thank you!

[handrews]

Note that OAS 3.2, which will hopefully by out by August, will introduce three new Tag Object fields parent, kind, and summary, with parent and kind offering two different ways to group tags. (this can be seen in the draft release notes at OAI/OpenAPI-Specification#4600)