[Keyboard] Support for dumbpad_v3x (#18663)

* feat: support for dumbpad_v3x

- all credit goes to
- ref: https://github.com/qmk/qmk_firmware/pull/16285

- included comment from noroadsleft
- ref: https://github.com/qmk/qmk_firmware/pull/16285#pullrequestreview-1038213899

* fix: add newline on every .c, .h, .mk files end

* feat: response to change https://github.com/qmk/qmk_firmware/pull/18663#discussion_r991515821

* feat: response to change https://github.com/qmk/qmk_firmware/pull/18663#discussion_r991516192

keyboards/dumbpad/v3x/info.json

@@ -0,0 +1,18 @@
+{
+    "keyboard_name": "dumbpad/v3x",
+    "url": "https://www.github.com/imchipwood/dumbpad",
+    "maintainer": "imchipwood",
+    "usb": {
+        "device_version": "0.1.0"
+    },
+    "layouts": {
+        "LAYOUT": {
+            "layout": [
+                                {"x":1, "y":0}, {"x":2, "y":0}, {"x":3, "y":0}, {"x":4, "y":0},
+                                {"x":1, "y":1}, {"x":2, "y":1}, {"x":3, "y":1}, {"x":4, "y":1},
+                                {"x":1, "y":2}, {"x":2, "y":2}, {"x":3, "y":2}, {"x":4, "y":2},
+                {"x":0, "y":3}, {"x":1, "y":3}, {"x":2, "y":3}, {"x":3, "y":3}, {"x":4, "y":3}
+            ]
+        }
+    }
+}