Fix Markdownlint error

Author: scottaddie

docs/azure/sdk/authentication/credential-chains.md

@@ -131,6 +131,5 @@ In the preceding output, notice that:
 - `EnvironmentCredential`, `WorkloadIdentityCredential`, and `ManagedIdentityCredential` each failed to acquire a Microsoft Entra access token, in that order.
 - The `DefaultAzureCredential credential selected:`-prefixed entry indicates the credential that was selected—`VisualStudioCredential` in this case. Since `VisualStudioCredential` succeeded, no credentials beyond it were used.
 
-
 <!-- LINKS -->
 [env-vars]: https://github.com/Azure/azure-sdk-for-net/blob/main/sdk/identity/Azure.Identity/README.md#environment-variables