Add option to add more verbose function documentation

[JoelKronander]

One cool feature could be to allow docgpt to output more verbose function docs.
Like with arguments and in a typical document parser style. e.g. Sphinx.

eg.

def my_function(my_arg: str, my_second_arg: float) -> float:
return len(my_arg)/my_second_arg

could add the function docstring

""" Counts the number of characters in the string, and divides by my_second_arg. """

Args:
my_arg: The string to count characters of
my_second_arg: the float to divide by.

Returns:
the result...
"""

Obviosuly the above example would make more sense for longer functions.