[appconfiguration] Fix snippets generation (Azure#33885)

### Packages impacted by this PR

- @azure/appconfiguration

### Issues associated with this PR

- Azure#33880

### Describe the problem that is addressed by this PR

Updates the snippets generation and adds an ignore to the CHANGELOG.

### What are the possible designs available to address the problem? If
there are more than one possible design, why was the one in this PR
chosen?


### Are there test cases added in this PR? _(If not, why?)_


### Provide a list of related PRs _(if any)_


### Command used to generate this PR:**_(Applicable only to SDK release
request PRs)_

### Checklists
- [ ] Added impacted package name to the issue description
- [ ] Does this PR needs any fixes in the SDK Generator?** _(If so,
create an Issue in the
[Autorest/typescript](https://github.com/Azure/autorest.typescript)
repository and link it here)_
- [ ] Added a changelog (if necessary)

Author: mpodwysocki

sdk/appconfiguration/app-configuration/CHANGELOG.md

@@ -1,3 +1,5 @@
+<!-- dev-tool snippets ignore -->
+
 # Release History
 
 ## 1.9.1 (Unreleased)

sdk/appconfiguration/app-configuration/README.md

@@ -80,19 +80,15 @@ More information about `@azure/identity` can be found [here](https://github.com/
 To authenticate with a resource in a [Sovereign Cloud](https://learn.microsoft.com/azure/active-directory/develop/authentication-national-cloud), you will need to set the `audience` in the `AppConfigurationClient` constructor options.
 
 ```ts snippet:AuthenticatingWithAzureSovereignCloud
-import { AppConfigurationClient } from "@azure/app-configuration";
+import { AppConfigurationClient, KnownAppConfigAudience } from "@azure/app-configuration";
 import { DefaultAzureCredential } from "@azure/identity";
 
 // The endpoint for your App Configuration resource
 const endpoint = "https://example.azconfig.azure.cn";
 // Create an AppConfigurationClient that will authenticate through AAD in the China cloud
-const client = new AppConfigurationClient(
-  endpoint,
-  new DefaultAzureCredential(),
-  {
-    audience: KnownAppConfigurationAudience.AzureChina
-  }
-);
+const client = new AppConfigurationClient(endpoint, new DefaultAzureCredential(), {
+  audience: KnownAppConfigAudience.AzureChina,
+});
 ```
 
 Note: When `audience` property is not defined, the SDK will default to Azure Public Cloud.