Usage with docstrings

Hey,
Is there any support for docstrings when using `flask-apispec` / `apispec`? So far I've seen only some random issues somehow related to that (#18?) but I couldn't figure it out, and don't see any examples of this.

It'd be nice to have some sort of integration/compatiblity layer between `apispec` and `sphinxdoc` (`@doc` and other decorators could even generate/extend `__doc__` on decorated methods/functions, but I'd really prefer it the other way around) as right now I end up with duplicated summaries in `@doc(summary="...")` and docstring itself.