Add back net sdk track 1 config for network (Azure#21103)

Author: fengzhou-msft

specification/network/resource-manager/readme.md

@@ -2552,6 +2552,7 @@ This is not used by Autorest itself.
 
 ``` yaml $(swagger-to-sdk)
 swagger-to-sdk:
+  - repo: azure-sdk-for-net
   - repo: azure-sdk-for-net-track2
   - repo: azure-sdk-for-python-track2
   - repo: azure-sdk-for-java