Added propper support for Lets split vitamins (#2559)

* Added support for the upcomming Lets_split vitamins included

* Updated readme

* Corrected header of readme

* Enabled RGB

* Broke everything

* broke some more shit

* Revert "broke some more shit"

This reverts commit 6ad68e6269cc0d04c16564ce9598dfd3db1e23c1.

* Revert "Broke everything"

This reverts commit feeee4e40db15a726f2292b6a9406ef45c1e54a7.

* Fixed USB detection, and RGB on slave

* started modifying readme, to use msys2

* Added support for the upcomming Lets_split vitamins included

* Updated readme

* Corrected header of readme

* Enabled RGB

* Broke everything

* broke some more shit

* Revert "broke some more shit"

This reverts commit 6ad68e6269cc0d04c16564ce9598dfd3db1e23c1.

* Revert "Broke everything"

This reverts commit feeee4e40db15a726f2292b6a9406ef45c1e54a7.

* Fixed USB detection, and RGB on slave

* started modifying readme, to use msys2

* Updated readme to reflect use of msys2 Added avrdude to msys path

* added avrdude option to msys installer

* Removed extra installation of avrdude

* Renamed to vitamins_included and implemented drashnas changes

* Fixed include guard

* Fixed some includes, and added avrdude target to docs.

* Fixed default keyboard

keyboards/vitamins_included/split_util.c

@@ -0,0 +1,20 @@
+#include <avr/io.h>
+#include <avr/wdt.h>
+#include <avr/power.h>
+#include <avr/interrupt.h>
+#include <util/delay.h>
+#include <avr/eeprom.h>
+#include "split_util.h"
+#include "matrix.h"
+#include "keyboard.h"
+#include "config.h"
+#include "timer.h"
+#include "debug.h"
+
+volatile bool isLeftHand = true;
+volatile bool contacted_by_master = false;
+
+// this code runs before the usb and keyboard is initialized
+void matrix_setup(void) {
+  isLeftHand = eeprom_read_byte(EECONFIG_HANDEDNESS);
+}