Add support for the chinese bluetooth keyboards.
This is the first layout manager, BTK1.
The keyboard should be kept vertically with the space key on the right.
There is no need to look at it for using LK: simply think to be clicking on a screen:
think of the keyboard like it was a touchscreen.
The only special key is the corner SHIFT which is used as <enter> to confirm a goto.
To advance to next pages such as in landables, turnpoints etc, use the top screen keys.