[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/billypython.c

@@ -0,0 +1,32 @@
+#include "billypython.h"
+
+__attribute__((weak))
+bool process_record_keymap(uint16_t keycode, keyrecord_t *record) {
+  return true;
+}
+
+bool process_record_user(uint16_t keycode, keyrecord_t *record) {
+  if (!process_record_keymap(keycode, record)) {
+    return false;
+  }
+
+  switch (keycode) {
+  case CLEAR:
+    if (record->event.pressed) {
+      SEND_STRING(SS_LCTRL("a") SS_TAP(X_DELETE));
+    }
+    return false;
+
+  default:
+    return true;
+  }
+}
+
+__attribute__((weak))
+uint32_t layer_state_set_keymap(uint32_t state) {
+  return state;
+}
+
+uint32_t layer_state_set_user(uint32_t state) {
+  return layer_state_set_keymap(state);
+}