[KeyVault] Update API tag for MHSM release (#10577)

* Update tag

* Update readme.md

Author: isra-fel

specification/keyvault/resource-manager/readme.md

@@ -29,18 +29,29 @@ openapi-type: arm
 tag: package-preview-2020-04
 ```
 
-
 ### Tag: package-preview-2020-04
 
 These settings apply only when `--tag=package-preview-2020-04` is specified on the command line.
 
 ```yaml $(tag) == 'package-preview-2020-04'
+input-file:
+  - Microsoft.KeyVault/stable/2019-09-01/keyvault.json
+  - Microsoft.KeyVault/stable/2019-09-01/providers.json
+  - Microsoft.KeyVault/preview/2020-04-01-preview/managedHsm.json
+```
+
+### Tag: package-preview-2020-04-full
+
+These settings apply only when `--tag=package-preview-2020-04-full` is specified on the command line.
+
+```yaml $(tag) == 'package-preview-2020-04-full'
 input-file:
   - Microsoft.KeyVault/preview/2020-04-01-preview/keyvault.json
   - Microsoft.KeyVault/preview/2020-04-01-preview/providers.json
   - Microsoft.KeyVault/preview/2020-04-01-preview/secrets.json
   - Microsoft.KeyVault/preview/2020-04-01-preview/managedHsm.json
 ```
+
 ### Tag: package-2019-09
 
 These settings apply only when `--tag=package-2019-09` is specified on the command line.