message: [Permissions] x-ms-permissions extension docs
diff: @@ -7,6 +7,7 @@ to generate your SDK using [DPG/RLC](https://aka.ms/azsdk/dpcodegen). This docum
  apply to your Swagger and/or Readme.
  Content:
  +
  - [Need for more/less SDK package(s)](#need-for-moreless-sdk-packages)
  - [Rename an operation](#rename-an-operation)
  - [Rename an operation group (or rename a sub-client)](#rename-an-operation-group-or-rename-a-sub-client)
  @@ -47,7 +48,9 @@ Note: If your operation contains an `_`, just change the second part as the firs
  ...
  "operationId": "MyGroup_SomethingElseToDoOperation",
  ```
  +
  becomes
  +
  ```json
  "operationId": "BuildTheThing",
  ...
  @@ -62,7 +65,9 @@ starts with the operation group prefix (there is likely many of them).
  ```json
  "operationId": "MyGroup_BuildSomethingElse",
  ```
  +
  becomes
  +
  ```json
  "operationId": "NewGroup_BuildSomethingElse",
  ```
  @@ -74,7 +79,9 @@ Don't use operation groups in your OperationID (remove them if they exist). For
  ```json
  "operationId": "MyGroup_BuildSomethingElse",
  ```
  +
  becomes
  +
  ```json
  "operationId": "BuildSomethingElse",
  ```
  @@ -86,12 +93,14 @@ becomes
  - For C#, use `single-top-level-client: true`
  For instance, this:
  +
  ```json
  "operationId": "MyGroup_BuildSomethingElse",
  ```
  Will create a subclient for MyGroup, that will have an operation called BuildSomethingElse.
  In various languages this could looks like (pseudo-code):
  +
  ```
  MyServiceClient(endpoint, credentials).MyGroup().BuildSomethingElse() // C#
  @@ -143,6 +152,7 @@ You will get this feedback if your operation is returning a list of objects. Con
  The full documentation for pageable is available here: https://github.com/Azure/autorest/blob/main/docs/extensions/readme.md#x-ms-pageable
  At a glance:
  +
  - Add `x-ms-pageable` node to your operation definition.
  - Make sure your return schema is an array of T (T could be anything).
  - `nextLinkName` can be `null` if your service do not support paging yet, otherwise should be the JSON key where the next link is (usually `nextLink`).
  @@ -171,9 +181,11 @@ You will get this feedback if your operation is a Long Running Operation (LRO),
  For most of the time, _there is no additional information to provide_ as the language runtime will auto-detect what polling mechanism to use.
  Some options can be configured with the node ["x-ms-long-running-operation-options"](https://github.com/Azure/autorest/blob/main/docs/extensions/readme.md#x-ms-long-running-operation-options):
  +
  - "final-state-via": Is here to prematuraly stop the polling in case your service do not respect the LRO correctly. _Do not use this option if you think your service respects the LRO guidelines, as you could break SDK_. In doubt about this option, please talk to the RestAPI stewardship board.
  Example:
  +
  ```json
  "x-ms-long-running-operation": true,
  "x-ms-long-running-operation-options": {
  