Migrate build target markers to keyboard.json (#23293)

keyboards/maple_computing/ivy/rev1/keyboard.json

@@ -0,0 +1,31 @@
+{
+    "keyboard_name": "Ivy",
+    "manufacturer": "Maple Computing",
+    "url": "",
+    "maintainer": "That-Canadian",
+    "usb": {
+        "vid": "0x1337",
+        "pid": "0x6012",
+        "device_version": "0.0.1"
+    },
+    "matrix_pins": {
+        "cols": ["F5", "B3", "D5"],
+        "rows": ["F1", "B2", "D3"]
+    },
+    "diode_direction": "COL2ROW",
+    "backlight": {
+        "driver": "timer",
+        "pin": "D2"
+    },
+    "processor": "atmega32u4",
+    "bootloader": "caterina",
+    "layouts": {
+        "LAYOUT": {
+            "layout": [
+                {"matrix": [0, 0], "x": 0, "y": 0},
+                {"matrix": [1, 1], "x": 1, "y": 0},
+                {"matrix": [2, 2], "x": 2, "y": 0}
+            ]
+        }
+    }
+}