[Keyboard] Add nullbitsco SCRAMBLE (#11078)

* Add SCRAMBLE

* Make requested changes to PR

* Add all layers to VIA keymap

Implement drashna's PR feedback in order to avoid random data within the layers in VIA.

* Make requested changes to PR

Implement fauxpark's PR feedback to clean up readme.md and rules.mk.

* Make changes based on PR feedback

-Changed VIA layers to enum
-Added info on how to enter the bootloader to readme

keyboards/nullbitsco/scramble/scramble.c

@@ -0,0 +1,40 @@
+/*
+Copyright 2020 Jay Greco
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include QMK_KEYBOARD_H
+
+// place overrides here
+void set_scramble_LED(uint8_t mode) {
+    switch(mode) {
+        case LED_ON:
+            setPinOutput(PIN_LED);
+            writePin(PIN_LED, GPIO_STATE_HIGH);
+        break;
+
+        case LED_DIM:
+            setPinInput(PIN_LED);
+        break;
+
+        case LED_OFF:
+            setPinOutput(PIN_LED);
+            writePin(PIN_LED, GPIO_STATE_LOW);
+        break;
+
+        default:
+        break;
+    }
+}