Missing blank line in numpydoc

[flexagoon]

Currently, the generated numpydoc annotations look like this:

"""[TODO:description]

Returns
-------
int
    [TODO:description]
"""

However, the numpydoc convention requires a blank line at the end of the annotation, so it should look like this:

"""[TODO:description]

Returns
-------
int
    [TODO:description]

"""