Added configurable key bindings (#472)

* added configurable key bindings

* added configurable key bindings

* Update README.rst

* Added flake8 fixes

* Move key config docs to docs

Co-authored-by: Cibin Mathew <cibinmathew@users.noreply.github.com>
Co-authored-by: Andreas Kloeckner <inform@tiker.net>