Display "Server Variable Object" descriptions

Content & configuration

Swagger/OpenAPI definition:

{
   "openapi": "3.0.3",
   "info": {
   	"title": "Wikibase REST API",
   	"version": "0.1",
   	"description": "OpenAPI definition of the Wikibase REST API",
   	"contact": {...},
   	"license": {...}
   },
   "paths": { "$ref": "./resources/index.json" },
   "components": {...},
   "tags": [...],
   "servers": [
   	{
   		"url": "https://{domain}/w/rest.php/wikibase/v0",
   		"variables": {
   			"domain": {
   				"default": "wikibase.example",
   				"description": "The domain of the Wikibase instance"
   			}
   		}
   	}
   ]
}

Swagger-UI configuration options:

SwaggerUI( { spec, dom_id: '#swagger' } );

Is your feature request related to a problem?

I'm frustrated when I add a description to an OpenAPI definition and it isn't rendered in the Swagger UI. In particular the "description" field on the Server Variable Object. In the example above this is the string "The domain of the Wikibase instance".

Describe the solution you'd like

I would like the "description" field on the Server Variable Object to be displayed.

Describe alternatives you've considered

Additional context

A very rough example:

Start at the SwaggerUI({ spec, dom_id: '#swagger' }) entry point and trace how the supplied OpenAPI servers and variables are rendered. Use the example definition as the fixture and verify that the Server Variable Object description appears in the generated UI; done means the "domain" description is visible.