* adding a custom mf68 keymap
* added custom tada68 keymap
* readme edit on tada68 map
* added mac fast-forward and rewind keybindings to tada68 emdarcher keymap
* tada68 keymap documentation and edits
* cleanup and edits
* typo fix in emdarcher's tada68 keymap
* cleaning up emdarcher keymap for tada68
* cleaned up emdarcher keymap for mf68
Ethan Durrant