[deviceupdate] make changes to readme in time for first release (#13240)

* make changes to readme in time for first release

* remove specification of 'sdk'  in path

Author: iscai-msft

specification/deviceupdate/data-plane/readme.python.md

@@ -4,14 +4,21 @@ These settings apply only when `--python` is specified on the command line.
 Please also specify `--python-sdks-folder=<path to the root directory of your azure-sdk-for-python clone>`.
 
 ```yaml
-  azure-arm: false
-  license-header: MICROSOFT_MIT_SMALL_NO_CODEGEN
-  namespace: azure.deviceupdate
-  package-name: azure-deviceupdate
-  package-version: 2020-09-01-preview
+  python-mode: create
+  license-header: MICROSOFT_MIT_NO_VERSION
+  namespace: azure.iot.deviceupdate
+  package-name: azure-iot-deviceupdate
+  package-version: 1.0.0b1
   clear-output-folder: true
-  add-credentials: true 
+  add-credentials: true
   credential-scopes: 6ee392c4-d339-4083-b04d-6b7947c6cf78/.default
-  no-namespace-folders: true
-  output-folder: $(python-sdks-folder)/sdk/deviceupdate/azure-deviceupdate/azure/deviceupdate
+```
+
+```yaml $(python-mode) == 'create'
+output-folder: $(python-sdks-folder)/deviceupdate/azure-iot-deviceupdate
+```
+
+```yaml $(python-mode) == 'update'
+no-namespace-folders: true
+output-folder: $(python-sdks-folder)/deviceupdate/azure-iot-deviceupdate/azure/iot/deviceupdate
 ```