DOC: Doc inheritance

[snowman2]

if you want to limit the duplication of the docstrings (because now all the attributes/methods that needed to be added to dispatch to self._crs have a copy of the docstring), I think it should be relatively easy to use a decorator that automatically adds the docstring of the cython class.

Something like

def inherit_doc():
    """
    A decorator adding the docstring from the equivalent `_CRS` method.
    """

    def decorator(decorated):
        original_method = getattr(_CRS, decorated.__name__, None)
        if original_method:
            doc = original_method.__doc__ or ""
        else:
            doc = ""

        decorated.__doc__ = doc
        return decorated

    return decorator

Originally posted by @jorisvandenbossche in #793 (comment)

[snowman2]

I have been thinking on this for a while. It definitely bothered me to have to copy over the docstrings from the cython _CRS class.

However, I think it is useful for developers to see the docstrings in the ,py file.

Current format:

    def to_json(self, pretty=False, indentation=2):
        """
        .. versionadded:: 2.4.0
        Convert the object to a JSON string.
        Parameters
        ----------
        pretty: bool
            If True, it will set the output to be a multiline string. Defaults to False.
        indentation: int
            If pretty is True, it will set the width of the indentation. Default is 2.
        Returns
        -------
        str
        """
        return self._crs.to_json(pretty=pretty, indentation=indentation)

Removing the docstrings:

    def to_json(self, pretty=False, indentation=2):
        return self._crs.to_json(pretty=pretty, indentation=indentation)

I am thinking I will leave it as is for the time being. I appreciate your suggestion @jorisvandenbossche as it was a nice solution that I thought would have been a good method to handle duplicate docstrings.