docs: update broken link of Openapi Object

docs/redoc-vendor-extensions.md

@@ -1,6 +1,6 @@
 # Redoc vendor extensions
 
 You can use the following [vendor extensions](https://redocly.com/docs/openapi-visual-reference/specification-extensions/) with Redoc.
 
 - [Redoc vendor extensions](#redoc-vendor-extensions)
   - [Swagger Object](#swagger-object)
@@ -50,10 +50,10 @@
       - [x-explicitMappingOnly example](#x-explicitmappingonly-example)
 
 ## Swagger Object
-Extends the OpenAPI root [OpenAPI Object](https://redocly.com/docs/openapi-visual-reference/openapi-1/)
+Extends the OpenAPI root [OpenAPI Object](https://redocly.com/docs/openapi-visual-reference/openapi)
 
 ### x-servers
 Backported from OpenAPI 3.0 [`servers`](https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.0.md#serverObject). Currently doesn't support templates.
 
 ### x-tagGroups
 
@@ -233,7 +233,7 @@
 #### Fixed fields
 | Field Name  | Type    | Description  |
 | :---------- | :------: | :----------- |
 | lang        | string   | Code sample language. Value should be one of the following [list](https://github.com/github/linguist/blob/master/lib/linguist/popular.yml) |
 | label       | string?   | Code sample label, for example `Node` or `Python2.7`, _optional_, `lang` is used by default |
 | source      | string   | Code sample source code |
 
@@ -258,13 +258,13 @@
 ### x-examples
 | Field Name     |  Type    | Description |
 | :------------- | :------: | :---------- |
 | x-examples | [Example Object](https://redocly.com/docs/openapi-visual-reference/example/)  | Object that contains examples for the request. Applies when `in` is `body` and mime-type is `application/json` |
 
 #### How to use with Redoc
 `x-examples` are rendered in the JSON tab on the right panel in Redoc.
 
 ## Response Object vendor extensions
 Extends the OpenAPI [Response Object](https://redocly.com/docs/openapi-visual-reference/response/).
 
 ### x-summary
 | Field Name     | Type   | Description |