Clarify workflow start method documentation

Removed redundant information about passing data to the workflow's start method.

Author: rmcdaniel

docs/defining-workflows/starting-workflows.md

@@ -13,8 +13,6 @@ $workflow = WorkflowStub::make(MyWorkflow::class);
 $workflow->start();
 ```
 
-You can also pass data to the workflow via the `start()` method. Any data you pass in will be sent to the workflow's `execute()` method.
-
 Once a workflow has been started, it will be executed asynchronously by a queue worker. The `start()` method returns immediately and does not block the current request.
 
 You can obtain an instance of an existing workflow using its workflow ID.