docs: missing T in import (#974)

# What does this PR do?

Missing T in import

## Test Plan

N/A doc update

## Sources

Please link relevant resources if necessary.


## Before submitting

- [X ] This PR fixes a typo or improves the docs (you can dismiss the
other checks if that's the case).
- [ ] Ran pre-commit to handle lint / formatting issues.
- [ ] Read the [contributor
guideline](https://github.com/meta-llama/llama-stack/blob/main/CONTRIBUTING.md),
      Pull Request section?
- [ ] Updated relevant documentation.
- [ ] Wrote necessary unit or integration tests.

docs/zero_to_hero_guide/README.md

@@ -208,7 +208,7 @@ In `test_llama_stack.py`, write the following code:
 
 ```python
 import os
-from llama_stack_client import LlamaStackClien
+from llama_stack_client import LlamaStackClient
 
 # Get the model ID from the environment variable
 INFERENCE_MODEL = os.environ.get("INFERENCE_MODEL")