* Add meck_tkl
* Fix configuration and pin assignment
* Rellocate A10 pin, as it is used by the USB DFU bootloader
* Add volume and media keys to the function keys layer
* Rellocate source files to the handwired keyboards folder and add documentation
* Review changes for PR
- Improve LAYOUT macro to match the keyboard layout.
- Use "kxy" as pin names on the LAYOUT macro.
- Remove unused mcuconf.h and halconf.h.
- Fix README.
* Improve layout macro naming
