Python: doc: fix the import (microsoft#2691)

### Motivation and Context

<!-- Thank you for your contribution to the semantic-kernel repo!
Please help reviewers and future users, providing the following
information:
  1. Why is this change required?
  2. What problem does it solve?
  3. What scenario does it contribute to?
  4. If it fixes an open issue, please link to the issue here.
--> 
typo in docs

### Description

<!-- Describe your changes, the overall approach, the underlying design.
These notes will help understanding how your code works. Thanks! -->
Just fix the error import

### Contribution Checklist

<!-- Before submitting this PR, please make sure: -->

- [x] The code builds clean without any errors or warnings
- [x] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [x] All unit tests pass, and I have added new tests where possible
- [x] I didn't break anyone 😄

---------

Co-authored-by: Abby Harrison <[email protected]>

Author: noahlias

python/README.md

@@ -26,7 +26,7 @@ AZURE_OPENAI_API_KEY=""
 
 ```python
 import semantic_kernel as sk
-from semantic_kernel.connectors.ai.open_ai import OpenAITextCompletion, AzureTextCompletion
+from semantic_kernel.connectors.ai.open_ai import OpenAIChatCompletion, AzureChatCompletion
 
 kernel = sk.Kernel()
 
@@ -36,7 +36,7 @@ kernel.add_chat_service("chat-gpt", OpenAIChatCompletion("gpt-3.5-turbo", api_ke
 
 # Alternative using Azure:
 # deployment, api_key, endpoint = sk.azure_openai_settings_from_dot_env()
-# kernel.add_text_completion_service("dv", AzureTextCompletion(deployment, endpoint, api_key))
+# kernel.add_chat_service("dv", AzureChatCompletion(deployment, endpoint, api_key))
 
 # Wrap your prompt in a function
 prompt = kernel.create_semantic_function("""