[Keyboard] Nebula12b (#17308)

Co-authored-by: Drashna Jaelre <drashna@live.com>
Co-authored-by: Ryan <fauxpark@gmail.com>
Co-authored-by: yiancar <yiancar@gmail.com>

keyboards/spaceholdings/nebula12b/info.json

@@ -0,0 +1,12 @@
+{
+    "keyboard_name": "NEBULA12B",
+    "url": "",
+    "maintainer": "yiancar",
+    "layouts": {
+        "LAYOUT_all": {
+            "layout": [
+                {"x":0, "y":0}, {"x":1, "y":0}, {"x":2, "y":0}, {"x":0, "y":1}, {"x":1, "y":1}, {"x":2, "y":1}, {"x":0, "y":2}, {"x":1, "y":2}, {"x":2, "y":2}, {"x":0, "y":3}, {"x":1, "y":3}, {"x":2, "y":3}
+            ]
+        }
+    }
+}