[Keyboard] Add YMDK NP24 (ATmega32U4 with 6 RGB LEDs) (#12120)

keyboards/ymdk/np24/u4rgb6/readme.md

@@ -0,0 +1,18 @@
+# YMDK NP24 U4 RGB6
+
+24 key number-pad with 6 RGB LEDs on the bottom (black PCB) sold by YMDK on Aliexpress (https://ymdk.aliexpress.com/store/429151).
+
+Not to be confused with the 8 RGB LED version (white PCB) that has an ATmega32A ("ymdk_np21").
+
+* Keyboard Maintainer: [QMK Community](https://github.com/qmk)
+* Hardware Supported: ATmega32U4
+
+Make example for this keyboard (after setting up your build environment):
+
+    make ymdk/np24/u4rgb6:default
+
+Flashing example for this keyboard:
+
+    make ymdk/np24/u4rgb6:default:flash
+
+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).