Hello,

In Airflow 2, we've moved some configuration options to the new section. We also changed the names of some of the configuration options. This is confusing for users who are familiar with the old option and section names.  It would be great if we could add information to the documentation that points to the new name of the options.

https://github.com/apache/airflow/blob/8f48f12128e0d985c6de2603902524859fecbca8/airflow/configuration.py#L139-L169

> 'The {old} option in [{section}] has been renamed to {new}
> 'The {old_key} option in [{old_section}] has been moved to the {new_key} option in '
> '[{new_section}]

Best regards,
Kamil Breguła

tests/core/test_configuration.py
assert 'key4_result' == test_conf.get('test', 'key4')
        assert 'value6' == test_conf.get('another', 'key6')
        assert 'hello' == test_conf.get('test', 'key1', fallback='fb')
        assert 'value6' == test_conf.get('another', 'key6', fallback='fb')
        assert 'fb' == test_conf.get('another', 'key7', fallback='fb')
        assert test_conf.getboolean('another', 'key8_boolean', fallback='True') is True
        assert 10 == test_conf.getint('another', 'key8_int', fallback='10')
        assert 1.0 == test_conf.getfloat('another', 'key8_float', fallback='1')
        assert test_conf.has_option('test', 'key1')
        assert test_conf.has_option('test', 'key2')
        assert test_conf.has_option('test', 'key3')
        assert test_conf.has_option('test', 'key4')
        assert not test_conf.has_option('test', 'key5')
        assert test_conf.has_option('another', 'key6')
        cfg_dict = test_conf.as_dict(display_sensitive=True)
        assert 'cmd_result' == cfg_dict['test']['key2']
        assert 'key2_cmd' not in cfg_dict['test']
        
        
        cfg_dict = test_conf.as_dict(include_cmds=False, display_sensitive=True)
        assert 'key4' not in cfg_dict['test']
        assert 'printf key4_result' == cfg_dict['test']['key4_cmd']
    @mock.patch("airflow.providers.hashicorp._internal_client.vault_client.hvac")
    @conf_vars(
        {
            ("secrets", "backend"): "airflow.providers.hashicorp.secrets.vault.VaultBackend",
            ("secrets", "backend_kwargs"): '{"url": "http://127.0.0.1:8200", "token": "token"}',
        }
    )
    def test_config_from_secret_backend(self, mock_hvac):