* Refactor layout macro names
Update the names of the layout macros to reflect QMK's desired usage.
- KEYMAP renamed to LAYOUT
- colinta keymap updated accordingly
- KC_KEYMAP renamed to LAYOUT_kc
- mtdjr keymap updated accordingly
* Update xd75.h to use #pragma once include guard
* Update keymaps to use QMK_KEYBOARD_H
* Refactor default keymap
- updated to use layout macro
- remove deprecated action_get_macro function
- add functions from QMK keymap.c template
- process_record_user
- matrix_init_user
- matrix_scan_user
- led_set_user
* Update supporting files
- updated config.h files to use #pragma once include guard
- remove errant QUANTUM_DIR code block
* Rename readme files to fully lowercase filenames
* Restructure keyboard readme
Updated the readme to better align with the current QMK template.
* Bugfixes to supporting files
* Use standard KC_ALGR, remove language-specific redefinitions
* Use ALGR instead of ALTGR in BÉPO and Canadian multilingual keymaps
* Remove BE_LALT, BE_LGUI aliases
* Add standard ALGR defition, remove (re)definitions from language files
* Use ALGR(kc) consistently in ALTGR(kc) aliases
* Non-Nordic keymaps should not use NO_ALGR
* Add standard KC_ALGR definition
* Update docs with ALGR and KC_ALGR
* Update SS_ALGR and ALGR_T aliases
* Added a heavily customized German keymap to the XD75RE
* A heavily customized alternative layout for the XD75, for German users
* Fixed capitalization, removed unnecessary files
* Hopefully fixed capitalization, some keymap changes
