Update quick-start.md (#3461)

# Description

Cleanup

# All Promptflow Contribution checklist:
- [x] **The pull request does not introduce [breaking changes].**
- [x] **CHANGELOG is updated for new features, bug fixes or other
significant changes.**
- [x] **I have read the [contribution guidelines](../CONTRIBUTING.md).**
- [ ] **Create an issue and link to the pull request to get dedicated
review from promptflow team. Learn more: [suggested
workflow](../CONTRIBUTING.md#suggested-workflow).**

## General Guidelines and Best Practices
- [x] Title of the pull request is clear and informative.
- [x] There are a small number of commits, each of which have an
informative message. This means that previously merged commits do not
appear in the history of the PR. For more information on cleaning up the
commits in your PR, [see this
page](https://github.com/Azure/azure-powershell/blob/master/documentation/development-docs/cleaning-up-commits.md).

### Testing Guidelines
- [x] Pull request includes test coverage for the included changes.

Co-authored-by: Clement Wang <47586720+wangchao1230@users.noreply.github.com>

docs/how-to-guides/quick-start.md

@@ -80,7 +80,7 @@ def chat(question: str = "What's the capital of France?") -> str:
     return output
 ```
 
-Flow can be a python function or class or a yaml file describe a DAG which encapsulate your LLM application logic.
+Flow can be a python function or class or a yaml file describing a DAG which encapsulates your LLM application logic.
 Learn more on the [flow concept](../concepts/concept-flows.md) and how to [Develop a flow](./develop-a-flex-flow/index.md).
 
 See the full example of this python file in: [Minimal Chat](https://github.com/microsoft/promptflow/tree/main/examples/flex-flows/chat-minimal).
@@ -94,13 +94,13 @@ Test the flow with your favorite experience: CLI, SDK or UI.
 :::{tab-item} CLI
 :sync: CLI
 
-`pf` is the CLI command you get when install `promptflow` package. Learn more on features of `pf` CLI in[reference doc](https://microsoft.github.io/promptflow/reference/pf-command-reference.html).
+`pf` is the CLI command you get when you install the `promptflow` package. Learn more about features of the `pf` CLI in the [reference doc](https://microsoft.github.io/promptflow/reference/pf-command-reference.html).
 
 ```sh
 pf flow test --flow flow:chat --inputs question="What's the capital of France?"
 ```
 
-You will get some output like below in terminal.
+You will get some output like the following in your terminal.
 ```text
 Prompt flow service has started...
 You can view the trace detail from the following URL:
@@ -110,7 +110,7 @@ The capital of France is Paris
 
 ```
 
-Click the trace url printed, you will see a trace UI which help you understand what's the actual llm call heppend behind the scenes.
+If you click the trace URL printed, you will see a trace UI which helps you understand the actual LLM call that happened behind the scenes.
 ![trace_ui](../media/how-to-guides/quick-start/flow_test_trace_ui.png)
 
 
@@ -119,7 +119,7 @@ Click the trace url printed, you will see a trace UI which help you understand w
 :::{tab-item} SDK
 :sync: SDK
 
-Call the chat function with your question. Assume you have a `flow.py` file with below content.
+Call the chat function with your question. Assume you have a `flow.py` file with the following content.
 ```python
 if __name__ == "__main__":
     from promptflow.tracing import start_trace
@@ -130,7 +130,7 @@ if __name__ == "__main__":
     print(result)
 ```
 
-Run you script with `python flow.py`, and you will get some outputs like below:
+Run the script with `python flow.py`, and you will get some output like below:
 ```text
 Prompt flow service has started...
 You can view the trace detail from the following URL:
@@ -140,7 +140,7 @@ The capital of France is Paris
 
 ```
 
-Click the trace url printed, you will see a trace UI which help you understand what's the actual llm call heppend behind the scenes.
+If you click the trace URL printed, you will see a trace UI which helps you understand the actual LLM call that happened behind the scenes.
 ![trace_ui](../media/how-to-guides/quick-start/flow_test_trace_ui.png)
 :::
 
@@ -159,7 +159,7 @@ The command will open a browser page like below:
 See more details of this topic in [Chat with a flow](./chat-with-a-flow/index.md).
 
 
-Click the "View trace" button, you will see a trace UI which help you understand what's the actual llm call heppend behind the scenes.
+Click the "View trace" button to see a trace UI which helps you understand the actual LLM call that happened behind the scenes.
 ![trace_ui](../media/how-to-guides/quick-start/flow_test_trace_ui.png)