Fix typo in webhook.md (external-secrets#4100)

Signed-off-by: Stas Alekseev <[email protected]>

Author: salekseev

docs/provider/webhook.md

@@ -4,7 +4,7 @@ External Secrets Operator can integrate with simple web apis by specifying the e
 
 ### Example
 
-First, create a SecretStore with a webhook backend.  We'll use a static user/password `root`:
+First, create a SecretStore with a webhook backend.  We'll use a static user/password `test`:
 
 ```yaml
 {% raw %}
@@ -124,4 +124,4 @@ spec:
 ```
 
 ### Webhook as generators
-You can also leverage webhooks as generators, following the same syntax. The only difference is that the webhook generator needs its source secrets to be labeled, as opposed to webhook secretstores. Please see the [generator-webhook](../api/generator/webhook.md) documentation for more information. 
+You can also leverage webhooks as generators, following the same syntax. The only difference is that the webhook generator needs its source secrets to be labeled, as opposed to webhook secretstores. Please see the [generator-webhook](../api/generator/webhook.md) documentation for more information.