* Align sendstring LUTs to 9 characters wide
* Replace 0 with XXXXXXX
* Use decimal 128 for LUT size
* Align heading comments
* Add ASCII table comments
* Add missing AltGr LUTs and adjust keycode LUTs accordingly
* Use pragma once
* Correct a couple more keycodes
* Capitalise "BÉPO"
* Also clean up the default tables
* Tidy up Belgian and Norman LUTs
Instead of having all sendstring keycode mappings in the main quantum.c
file, give each one its own file in keymap_extras that can be #included
in a user's keymap. If one is included, it will define the appropriate
lookup tables and overwrite the weak definitions in quantum.c.
(Including more than one sendstring definition will fail at compile
time.)
Update @rai-suta's test keymap to match, as well as the documentation.
