Keyboard: Add Big Series 2-, 3-, and 4-key boards (#3669)

* Implement magic 8-ball mode for big series switch

* LED Testing

* Add Ctrl+Alt+Del key mapping

* Add Windows lock (win+L) layout.

* Add Big Series 3-key

* Add Big Series 4-key

* Add Big Series 2-key

* Fix layout mapping for Big Series 3u

* Fix merge-conflict.

* Refactor bigseries boards into a single folder

keyboards/bigseries/3key/info.json

@@ -0,0 +1,12 @@
+{
+  "keyboard_name": "Big Series 3-Key",
+  "url": "",
+  "maintainer": "qmk",
+  "width": 12,
+  "height": 4,
+  "layouts": {
+    "LAYOUT": {
+      "layout": [{"x":0, "y":0, "w":4, "h":4}, {"x":1, "y":0, "w":4, "h":4}, {"x":2, "y":0, "w":4, "h":4}]
+    }
+  }
+}