Fetch a Qiskit tutorial from the IBM Quantum Learning Hub.
First, get the table of contents (toc) and check the tutorial names.
Tutorial names should be specified in lowercase with hyphens (e.g., "variational-quantum-eigensolver", "quantum-approximate-optimization-algorithm").
If the tutorial name is not found, it will return an error message.
Args:
tutorial_name (str): The name of the tutorial to fetch. Use "toc" for the table of contents.
If the tutorial name is not found, it will return an error message.
tutorial_name should be in lowercase and hyphenated (e.g., "variational-quantum-eigensolver", "quantum-approximate-optimization-algorithm").
Returns:
str: The tutorial content in Markdown format.