Parse docstrings for type information

[jakebailey]

Some docstrings contain type info (as opposed to stubs or type annotations). This info should be parsed and used best-effort.

There are many different possible formats; numpy, google, epydoc, etc.

See also: https://www.sphinx-doc.org/en/master/usage/extensions/napoleon.html

With examples that look like:

:param path: The path of the file to wrap
:type path: str
:param field_storage: The :class:`FileStorage` instance to wrap
:type field_storage: FileStorage
:param temporary: Whether or not to delete the file when the File
   instance is destructed
:type temporary: bool
:returns: A buffered writable file descriptor
:rtype: BufferedFileStorage

But also:

Args:
    path (str): The path of the file to wrap
    field_storage (FileStorage): The :class:`FileStorage` instance to wrap
    temporary (bool): Whether or not to delete the file when the File
       instance is destructed

Returns:
    BufferedFileStorage: A buffered writable file descriptor

Types are often not qualified, though, so may require some heuristic to figure out what type we actually think is being used.

[MikhailArkhipov]

We may also consider #533 since currently scraper makes print having no arguments while

def print():
    "print(value, ..., sep=' ', end='\\n', file=sys.stdout, flush=False)\n\nPrints the values to a stream, or to sys.stdout by default.\nOptional keyword arguments:\nfile:  a file-like object (stream); defaults to the current sys.stdout.\nsep:   string inserted between values, default a space.\nend:   string appended after the last value, default a newline.\nflush: whether to forcibly flush the stream."
    pass