[Core] Add getreuer's Autocorrect feature to core (#15699)

Co-authored-by: Albert Y <76888457+filterpaper@users.noreply.github.com>

quantum/quantum_keycodes.h

@@ -611,6 +611,10 @@ enum quantum_keycodes {
 
     UNICODE_MODE_EMACS,
 
+    AUTOCORRECT_ON,
+    AUTOCORRECT_OFF,
+    AUTOCORRECT_TOGGLE,
+
     // Start of custom keycode range for keyboards and keymaps - always leave at the end
     SAFE_RANGE
 };
@@ -799,6 +803,10 @@ enum quantum_keycodes {
 #define EH_LEFT MAGIC_EE_HANDS_LEFT
 #define EH_RGHT MAGIC_EE_HANDS_RIGHT
 
+#define CRT_ON AUTOCORRECT_ON
+#define CRT_OFF AUTOCORRECT_OFF
+#define CRT_TOG AUTOCORRECT_TOGGLE
+
 // GOTO layer - 256 layer max
 #define TO(layer) (QK_TO | ((layer)&0xFF))