Return a formatted string listing commands, HTTPie options, and HTTP
    actions.

def generate_help_text():
    """Return a formatted string listing commands, HTTPie options, and HTTP
    actions.
    """
    def generate_cmds_with_explanations(summary, cmds):
        text = '{0}:\n'.format(summary)
        for cmd, explanation in cmds:
            text += '\t{0:<10}\t{1:<20}\n'.format(cmd, explanation)
        return text + '\n'

    text = generate_cmds_with_explanations('Commands', ROOT_COMMANDS.items())
    text += generate_cmds_with_explanations('Options', OPTION_NAMES.items())
    text += generate_cmds_with_explanations('Actions', ACTIONS.items())
    text += generate_cmds_with_explanations('Headers', HEADER_NAMES.items())
    return text