Add letters to English QWERTZ and QWERTY and add Czech xml

[ikanakova]

It's clear to me that I have to make more changes somewhere, but I didn't dare - I'm not that good a programmer :-(

[tibbi]

and the new file isnt even added anywhere in the code, how have you tested if it works well?

[tibbi]

that file is almost the same as the english one, not worth adding.. Thanks though