def METHOD_NAME(self, yaml_file_path):
    """Return HTML for a given YAML file.
    Args:
        yaml_file_path: Location of YAML file to convert (str).
    Returns:
        String of HTML
    Raises:
        CouldNotFindYAMLFileError: When a given YAML file cannot be found.
    """
    activity_steps_data = self.load_yaml_file(yaml_file_path)
    # Check all images exist
    activity_image_filenames = set()
    for step_data in activity_steps_data:
        activity_image_filenames.add(step_data.get('image'))
    find_image_files(activity_image_filenames, yaml_file_path)
    # Render as HTML
    html = render_to_string(
        'at_home/activity_steps.html',
        {'activity_steps': activity_steps_data}
    )
    return html