{storage} Add new api version in readme (#13034)

* add api

* refine

specification/storage/resource-manager/readme.python.md

@@ -18,6 +18,7 @@ Generate all API versions currently shipped for this package
 ```yaml $(multiapi)
 clear-output-folder: true
 batch:
+  - tag: package-2021-01
   - tag: package-2020-08-preview
   - tag: package-2019-06
   - tag: package-2019-04
@@ -38,7 +39,15 @@ output-folder: $(python-sdks-folder)/storage/azure-mgmt-storage/azure/mgmt/stora
 clear-output-folder: false
 perform-load: false
 ```
+### Tag: package-2021-01 and python
 
+These settings apply only when `--tag=package-2021-01 --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 $(tag) == 'package-2021-01'
+namespace: azure.mgmt.storage.v2021_01_01
+output-folder: $(python-sdks-folder)/storage/azure-mgmt-storage/azure/mgmt/storage/v2021_01_01
+```
 ### Tag: package-2020-08-preview and python
 
 These settings apply only when `--tag=package-2020-08-preview --python` is specified on the command line.