docs: Propose adding examples for all `function_tool` parameters

[muhammadhamidrazasidtechno]

This issue proposes enhancing the documentation by adding clear code examples for each parameter of the @function_tool decorator.

Currently, the documentation could be improved by providing specific examples for how to use each of the following parameters:

• name_override: An example showing how to explicitly set a tool's name.
• description_override: An example demonstrating how to provide a custom description for a tool.
• docstring_style: An example of how to use a specific docstring style to parse tool information.
• use_docstring_info: An example that shows when and how to control whether docstring information is used.
• failure_error_function: A clear example demonstrating how to use a custom function for handling tool errors.
• strict_mode: An example that explains the behavior when strict mode is enabled or disabled.
• is_enabled: An example that shows how to dynamically enable or disable a tool based on a condition.

Adding these examples will provide developers with a comprehensive and easy-to-understand guide for configuring their tools, making the SDK more accessible and user-friendly.

Here is a code example for the failure_error_function parameter:

from agents import function_tool, RunContextWrapper
from typing import Any

def my_custom_error_function(context: RunContextWrapper[Any], error: Exception) -> str:
    """A custom function to provide a user-friendly error message."""
    print(f"A tool call failed with the following error: {error}")
    return "An internal server error occurred. Please try again later."

@function_tool(failure_error_function=my_custom_error_function)
def get_user_profile(user_id: str) -> str:
    """Fetches a user profile from a mock API.
    
    This function demonstrates a "flaky" or failing API call.
    """
    if user_id == "user_123":
        return "User profile for user_123 successfully retrieved."
    else:
        raise ValueError(f"Could not retrieve profile for user_id: {user_id}. API returned an error.")

[seratch]

As you already noticed, this can be improved by #1354