title: How can I use the Swagger UI open openapi document?
body: <p>I check out the latest code from Swagger UI 3.25.0 on github and add some features like saving and loading requet data. It works fine with Swagger 2.0 doc which has a json file like this</p>
  
  <pre><code>{
     "swagger":"2.0",
     "info":{
        "version":"1.0",
        "title":"Order api",
        "description":"Order api"
     },
     "paths":{
        "/api/v1/internal/orderdispatch/DispatchOrder/DispatchOrdersByIdList":{
           "post":{
              "tags":[
                 "Myaz.OrderDispatch.API.Controllers/DispatchOrder"
              ],
              "operationId":"POST_api_v1_internal_orderdispatch_DispatchOrder_DispatchOrdersByIdList",
              "consumes":[
                 "application/json-patch+json",
                 "application/json",
                 "text/json",
                 "application/*+json"
              ],
              "produces":[
                 "application/json"
              ],
              "parameters":[
                 {
                    "name":"salesOrderIdList",
                    "in":"body",
                    "required":false,
                    "schema":{
                       "uniqueItems":false,
                       "type":"array",
                       "items":{
                          "type":"string"
                       }
                    }
                 }
              ],
              "responses":{
                 "200":{
                    "description":"Success"
                 }
              },
              "deprecated":false
           }
        },
     }
  }
  </code></pre>
  
  <p>But it seems that it can't open the OAS 3.0 doc which has the following structure.</p>
  
  <pre><code>{
    "openapi": "3.0.1",
    "info": {
      "title": "My API",
      "version": "v1"
    },
    "paths": {
      "/api/v1/OrderRouter/SalesOrder/CreateSalesOrder": {
        "post": {
          "tags": [
            "SalesOrder"
          ],
          "requestBody": {
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/Myaz.ERP.Model.OrderRouter.ViewModel.SalesOrderViewModel"
                }
              },
              "text/json": {
                "schema": {
                  "$ref": "#/components/schemas/Myaz.ERP.Model.OrderRouter.ViewModel.SalesOrderViewModel"
                }
              },
              "application/*+json": {
                "schema": {
                  "$ref": "#/components/schemas/Myaz.ERP.Model.OrderRouter.ViewModel.SalesOrderViewModel"
                }
              }
            }
          },
          "responses": {
            "200": {
              "description": "Success"
            }
          }
        }
      },
    }
  }
  </code></pre>
  
  <p>Currently I'm using asp.net core 3.1 which only support OAS doc. So how can I use swagger UI to show OAS 3.0 doc?
  Thanks in advance.</p>