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

airflow/configuration.py
"""
        Remove an option if it exists in config from a file or
        default config. If both of config have the same option, this removes
        the option in both configs unless remove_default=False.
        """
        if super().has_option(section, option):
            super().remove_option(section, option)
        if self.airflow_defaults.has_option(section, option) and remove_default:
            self.airflow_defaults.remove_option(section, option)
    def getsection(self, section: str) -> Optional[Dict[str, Union[str, int, float, bool]]]:
        """
        Returns the section as a dict. Values are converted to int, float, bool
        as required.
        :param section: section from the config
        :rtype: dict
        """
        if not self.has_section(section) and not self.airflow_defaults.has_section(section):
            return None
        if self.airflow_defaults.has_section(section):
            _section = OrderedDict(self.airflow_defaults.items(section))
        else:
            _section = OrderedDict()
        if self.has_section(section):
            _section.update(OrderedDict(self.items(section)))
        section_prefix = f'AIRFLOW__{section.upper()}__'
        for env_var in sorted(os.environ.keys()):
            if env_var.startswith(section_prefix):