[Job Router] Modify readme to include common transformations (#19433)

* modify readme to include common transformations

* missing transformation for exception rule

Author: sarkar-rajarshi

specification/communication/data-plane/JobRouter/readme.csharp.md

@@ -0,0 +1,15 @@
+## C#
+
+These settings apply only when `--csharp` is specified on the command line.
+Please also specify `--csharp-sdks-folder=<path to "SDKs" directory of your azure-sdk-for-net clone>`.
+
+``` yaml $(csharp)
+csharp:
+  azure-arm: true
+  license-header: MICROSOFT_MIT_NO_VERSION
+  namespace: Azure.Communication.JobRouter
+  payload-flattening-threshold: 1
+  output-folder: $(csharp-sdks-folder)/communication/Azure.Communication.JobRouter/src/Generated
+  clear-output-folder: true
+  client-side-validation: false
+```

specification/communication/data-plane/JobRouter/readme.md

@@ -38,6 +38,40 @@ input-file:
   - preview/2021-10-20-preview2/communicationservicejobrouter.json
 title:
   Azure Communication Services
+directive:
+# Set reference to WorkerSelectorAttachment in ClassificationPolicy
+  - from: swagger-document
+    where: "$.definitions.ClassificationPolicy.properties.workerSelectors.items"
+    transform: >
+      $["$ref"] = "#/definitions/WorkerSelectorAttachment";
+# Set reference to QueueSelectorAttachment in ClassificationPolicy  
+  - from: swagger-document
+    where: "$.definitions.ClassificationPolicy.properties.queueSelectors.items"
+    transform: >
+      $["$ref"] = "#/definitions/QueueSelectorAttachment";
+# Set reference to WorkerSelectorAttachment in PagedClassificationPolicy  
+  - from: swagger-document
+    where: "$.definitions.PagedClassificationPolicy.properties.workerSelectors.items"
+    transform: >
+      $["$ref"] = "#/definitions/WorkerSelectorAttachment";
+# Set reference to QueueSelectorAttachment in PagedClassificationPolicy
+  - from: swagger-document
+    where: "$.definitions.PagedClassificationPolicy.properties.queueSelectors.items"
+    transform: >
+      $["$ref"] = "#/definitions/QueueSelectorAttachment";
+
+# Set reference to ExceptionAction in ExceptionRule
+  - from: swagger-document
+    where: "$.definitions.ExceptionRule.properties.actions"
+    transform: >
+      $.type = "object";
+      $.additionalProperties["$ref"] = "#/definitions/ExceptionAction";
+
+# Rename CommunicationError to JobRouterError
+  - from: swagger-document
+    where: '$.definitions.CommunicationError'
+    transform: >
+      $["x-ms-client-name"] = "JobRouterError";
 ```
 
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