[Keymap] Add my personal userspace and update my keymaps (#5128)

* Add billypython userspace and dz60 keymap

* Disable Bootmagic in dz60:billypython keymap

* Update whitefox:billypython keymap with userspace changes

Also remove numpad layer

users/billypython/tap_dance.h

@@ -0,0 +1,9 @@
+#pragma once
+
+#include "quantum.h"
+
+#define RSF_RCT TD(TD_RSF_RCT)
+
+enum tap_dance {
+  TD_RSF_RCT,
+};