Lstm benchmark example fix (#625)
Lstm benchmark example fix (#625)

* bugfix

* type annotation

* formatting

* reformat import statements

Co-authored-by: Kádár Ákos <54ce34a324fc8bd5b2c48975287ea871dbbbe28c@onyx.uvt.nl>
Co-authored-by: svlandeg <4da0510fc9ac6504702ef47a8b3fc3d8fc7be21b@github.com>
explosion/thinc,explosion/thinc,explosion/thinc,explosion/thinc