update code block syntax for package

Author: rishabh-f5

content/nginxaas-azure/getting-started/nginx-configuration/nginx-configuration-azure-cli.md

@@ -129,7 +129,7 @@ az nginx deployment configuration analyze --deployment-name $DEPLOYMENT_NAME \
 
    Upload a package with config files and protected files:
 
-   ```bash
+   ```shell
    az nginx deployment configuration create --deployment-name myDeployment \
       --resource-group myResourceGroup --root-file nginx.conf --name default \
       --package data="$TAR_DATA" \