[Keyboard] Add Quefrency Rev. 3 (#11578)

* Update default VIA layout option

* Add Quefrency Rev. 3

* Update readme

* Add GPL2 headers

* Update keyboards/keebio/quefrency/rev3/config.h

Co-authored-by: Ryan <fauxpark@gmail.com>

Co-authored-by: Ryan <fauxpark@gmail.com>

keyboards/keebio/quefrency/quefrency.h

@@ -8,6 +8,9 @@
 #ifdef KEYBOARD_keebio_quefrency_rev2
     #include "rev2.h"
 #endif
+#ifdef KEYBOARD_keebio_quefrency_rev3
+    #include "rev3.h"
+#endif
 
 // Used to create a keymap using only KC_ prefixed keys
 #define LAYOUT_kc( \