Handle inputs as per usual (which however is a bit weak, is it goes through
key by key and not the entire line), batch all events such that all events
are handled before the next frame is rendered. For this the `App.start`
function needs to become configurable, such that it changes the termios as
configured (hence it is currently all commented out for testing).
A corresponding example has been added, which is very minimalistic as of now,
but will add further functionality to test the corresponding workflow that is
usual in `zterm` such that it in the best case only a swap in the renderer to
switch from alternate mode drawing to direct drawing.
