Update/remove obsolete docs (Azure#24946)

Author: mikekistler

documentation/Getting started with OpenAPI specifications.md

@@ -8,14 +8,16 @@ OpenAPI Specification (formerly known as Swagger Specification) is an API descri
 Currently, we only support `OpenAPI Specification 2.0` or `Swagger V2.0`.
 
 ### Helpful Resources
+
 * **[`Understanding the GitHub flow`](https://guides.github.com/introduction/flow/)**
-* **[`Microsoft REST-API guidelines`](https://github.com/microsoft/api-guidelines/blob/vNext/Guidelines.md)**]
+* **[`CONTRIBUTING.md`](https://github.com/Azure/azure-rest-api-specs/blob/main/CONTRIBUTING.md)**
+* **[`Azure REST API guidelines`](https://github.com/microsoft/api-guidelines/blob/vNext/Azure/Guidelines.md)**
+* **[`Azure OpenAPI Style Guide`](https://github.com/Azure/azure-api-style-guide/blob/main/openapi-style-guide.md)**
 * **[`Resource Provider Guidelines`](https://aka.ms/rpguidelines)**
-* **[`Sample directory structure for swagger`](https://github.com/Azure/azure-rest-api-specs/wiki#directory-structure)**
+* **[`Directory structure`](https://github.com/Azure/azure-rest-api-specs/blob/main/README.md#directory-structure)**
 * **[`Structure of a Swagger specification`](https://github.com/Azure/azure-rest-api-specs/blob/master/documentation/creating-swagger.md)**
 * **[`Sample Swagger specification`](https://github.com/Azure/azure-rest-api-specs/blob/master/documentation/samplefiles/Microsoft.YourServiceName/stable/YYYY-MM-DD/YourServiceName.json)**
 * **[`Sample Readme.md`](https://github.com/Azure/azure-rest-api-specs/blob/master/documentation/samplefiles/samplereadme.md)**
-* **[`Swagger style guide`](https://github.com/Azure/azure-rest-api-specs/blob/master/documentation/swagger-style-cheatsheet.md)**
 * **[`Authoring good Swagger descriptions`](https://github.com/Azure/azure-rest-api-specs/blob/master/documentation/swagger-authoring-descriptions.md)**
 * **[`Validation tools`](https://github.com/Azure/azure-rest-api-specs/blob/master/documentation/SwaggerValidationTools.md)**
    * [`Validation checks through automated tools`](https://github.com/Azure/azure-rest-api-specs/blob/master/documentation/openapi-authoring-automated-guidelines.md)