config readme (#16645)

Author: BigCat20196

specification/monitor/resource-manager/readme.md

@@ -73,6 +73,15 @@ input-file:
 - Microsoft.Insights/stable/2021-04-01/dataCollectionRules_API.json
 ```
 
+### Tag: package-2021-09-01-only
+
+These settings apply only when `--tag=package-2021-09-01-only` is specified on the command line.
+
+``` yaml $(tag) == 'package-2021-09-01-only'
+input-file:
+- Microsoft.Insights/stable/2021-09-01/actionGroups_API.json
+```
+
 ### Tag: package-2021-07
 
 These settings apply only when `--tag=package-2021-07` is specified on the command line

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

@@ -18,6 +18,7 @@ Generate all API versions currently shipped for this package
 ```yaml $(multiapi) && $(track2)
 clear-output-folder: true
 batch:
+  - tag: package-2021-09-01-only
   - tag: package-2021-05-01-preview-only
   - tag: package-2021-04-only
   - tag: package-2020-10-only
@@ -51,6 +52,16 @@ clear-output-folder: false
 perform-load: false
 ```
 
+### Tag: package-2021-09-01-only and python
+
+These settings apply only when `--tag=package-2021-09-01-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-2021-09-01-only'
+namespace: $(python-base-namespace).v2021_09_01
+output-folder: $(python-sdks-folder)/$(python-base-folder)/v2021_09_01
+```
+
 ### Tag: package-2021-07-01-preview-only and python
 
 These settings apply only when `--tag=package-2021-07-01-preview-only --python` is specified on the command line.