docs: sync Haystack API reference on Docusaurus (#11338)

Co-authored-by: sjrl <10526848+sjrl@users.noreply.github.com>

Author: HaystackBot

docs-website/reference/haystack-api/generators_api.md

@@ -35,7 +35,7 @@ from haystack.utils import Secret
 client = AzureOpenAIGenerator(
     azure_endpoint="<Your Azure endpoint e.g. `https://your-company.azure.openai.com/>",
     api_key=Secret.from_token("<your-api-key>"),
-    azure_deployment="<this a model name, e.g.  gpt-4.1-mini>")
+    azure_deployment="<this is a model name, e.g. gpt-4.1-mini>")
 response = client.run("What's Natural Language Processing? Be brief.")
 print(response)
 ```
@@ -182,7 +182,7 @@ messages = [ChatMessage.from_user("What's Natural Language Processing?")]
 client = AzureOpenAIChatGenerator(
     azure_endpoint="<Your Azure endpoint e.g. `https://your-company.azure.openai.com/>",
     api_key=Secret.from_token("<your-api-key>"),
-    azure_deployment="<this a model name, e.g. gpt-4.1-mini>")
+    azure_deployment="<this is a model name, e.g. gpt-4.1-mini>")
 response = client.run(messages)
 print(response)
 ```