Prepare ymdk/ymd75 for rev4 (qmk#21484)

keyboards/ymdk/ymd75/readme.md

@@ -2,23 +2,11 @@
 
 75% keyboard from YMDK. YMDK sell the board and name it "YMD75", however revision 1 of the PCB has "MT84" printed on both sides.
 
-This firmware can also be flashed onto the KBDFans KBD75 Round 2 Bootmapper Client boards sold during the mid-2018 timeframe.
-
-* Keyboard Maintainer: [Wayne K Jones](github.com/WarmCatUK)
-* Hardware Supported: 
-   - rev1 (ATmega32a) 
-   - rev2 (ATmega32a) 
-   - rev3 (ATmega32u4)
-* Hardware Availability: <https://www.aliexpress.com/item/32812690592.html>
-
-Make example for this keyboard (after setting up your build environment):
-
-    make ymdk/ymd75/rev1:default
-
-Flashing example for this keyboard ([after setting up the bootloadHID flashing environment](https://docs.qmk.fm/#/flashing_bootloadhid))
-
-    make ymdk/ymd75/rev1:default:flash
-
-**Reset Key**: Hold down the key located at *Key below the top right key*, commonly programmed as *Backspace* while plugging in the keyboard. On PCB revision 2, enter the bootloader by holding `L_CTRL` while plugging in the keyboard.
+* Hardware Supported:
+    - rev1 (ATmega32a)
+        - This firmware can also be flashed onto the KBDFans KBD75 Round 2 Bootmapper Client boards sold during the mid-2018 timeframe.
+    - rev2 (ATmega32a)
+    - rev3 (ATmega32u4)
+    - rev4 (APM32F103)
 
 See the [build environment setup](https://docs.qmk.fm/#/getting_started_build_tools) and the [make instructions](https://docs.qmk.fm/#/getting_started_make_guide) for more information. Brand new to QMK? Start with our [Complete Newbs Guide](https://docs.qmk.fm/#/newbs).

keyboards/ymdk/ymd75/rev1/info.json

@@ -1,5 +1,11 @@
 {
+    "keyboard_name": "YMD75 / MT84",
+    "manufacturer": "YMDK",
+    "url": "",
+    "maintainer": "qmk",
     "usb": {
+        "vid": "0x20A0",
+        "pid": "0x422D",
         "device_version": "1.0.0"
     },
     "matrix_pins": {
@@ -14,9 +20,27 @@
     "ws2812": {
         "driver": "i2c"
     },
+    "rgblight": {
+        "led_count": 16,
+        "animations": {
+            "alternating": true,
+            "breathing": true,
+            "christmas": true,
+            "knight": true,
+            "rainbow_mood": true,
+            "rainbow_swirl": true,
+            "rgb_test": true,
+            "snake": true,
+            "static_gradient": true,
+            "twinkle": true
+        }
+    },
     "indicators": {
         "caps_lock": "D1"
     },
+    "dynamic_keymap": {
+        "layer_count": 3
+    },
     "processor": "atmega32a",
     "bootloader": "bootloadhid",
     "layouts": {