Update readme.python.md (Azure#17746)

Author: msyyc

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

@@ -37,6 +37,7 @@ Generate all API versions currently shipped for this package
 clear-output-folder: true
 batch:
   - tag: package-2021-11-01-only
+  - tag: package-2021-10-01-only
   - tag: package-2021-08-01-only
   - tag: package-2021-07-01-only
   - tag: package-2021-04-01-only
@@ -81,6 +82,16 @@ namespace: azure.mgmt.compute.v2021_11_01
 output-folder: $(python-sdks-folder)/compute/azure-mgmt-compute/azure/mgmt/compute/v2021_11_01
 ```
 
+### Tag: package-2021-10-01-only
+
+These settings apply only when `--tag=package-2021-10-01-only --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-2021-10-01-only'
+namespace: azure.mgmt.compute.v2021_10_01
+output-folder: $(python-sdks-folder)/compute/azure-mgmt-compute/azure/mgmt/compute/v2021_10_01
+```
+
 ### Tag: package-2021-08-01-only
 
 These settings apply only when `--tag=package-2021-08-01-only --python` is specified on the command line.