Update readme.md

Author: ericshape

specification/sql/resource-manager/readme.md

@@ -148,6 +148,7 @@ input-file:
   - Microsoft.Sql/preview/2021-11-01-preview/VirtualNetworkRules.json
   - Microsoft.Sql/preview/2021-11-01-preview/WorkloadClassifiers.json
   - Microsoft.Sql/preview/2021-11-01-preview/WorkloadGroups.json
+  - Microsoft.Sql/preview/2021-11-01-preview/ManagedServerDnsAliases.json
 ```
 ### Tag: package-composite-v5