fix(docs): update workflow API example to include query parameter (#9640)

### Fix Missing Query Parameter in Documentation Example

#### Summary
This pull request addresses a missing query parameter in the Medusa documentation's example for making a request to the workflow endpoint.

#### Issue
The example in the documentation incorrectly shows:
```
curl http://localhost:9000/workflow
```
This causes an issue when running the workflow in code, specifically in `step-2`, where the `name` parameter is `undefined`. 

#### Expected Behavior
The correct curl command should include the `name` query parameter, like so:
```
curl http://localhost:9000/workflow?name=john
```

#### Code Example
Here is the code that demonstrates the issue:

```ts
const step2 = createStep("step-2", async ({ name }: WorkflowInput) => {
  return new StepResponse(`Hello ${name} from step two!`)
})
```

When running the incorrect curl command, the output for `step-2` returns:
```
"Hello undefined from step two!"
```

#### Fix
The pull request proposes updating the example curl command in the documentation to:
```
curl http://localhost:9000/workflow?name=john
```

This ensures that the `name` parameter is correctly passed and resolves the issue of `undefined` values in `step-2`.

#### Steps to Reproduce
1. Implement the workflow and API code as described in the [documentation](https://docs.medusajs.com/v2/basics/workflows#4-test-workflow).
2. Run the curl command:
   ```
   curl http://localhost:9000/workflow
   ```
3. The console will output `Hello undefined from step two!` due to the missing `name` parameter.

#### Suggested Resolution
Update the curl command in the [documentation](https://docs.medusajs.com/v2/basics/workflows#4-test-workflow) to:
```
curl http://localhost:9000/workflow?name=john
```

### Related Issue
Link to the issue: [Medusa Issue #9628](https://github.com/medusajs/medusa/issues/9628)

Co-authored-by: Carlos R. L. Rodrigues <37986729+carlos-r-l-rodrigues@users.noreply.github.com>

www/apps/book/app/basics/workflows/page.mdx

@@ -196,7 +196,7 @@ npm run dev
 Then, send a `GET` request to `/workflow`:
 
 ```bash
-curl http://localhost:9000/workflow
+curl http://localhost:9000/workflow?name=john
 ```
 
 You’ll receive the following response: