[Keyboard] add ogrn (#17983)

Co-authored-by: Drashna Jaelre <drashna@live.com>

keyboards/akb/ogrn/readme.md

@@ -0,0 +1,27 @@
+# akb/ogrn
+
+![akb/ogrn](https://i.imgur.com/qbolyMal.png)
+
+Numpad for the OGR keyboard by AKB
+
+* Keyboard Maintainer: [akb](https://alchemistkeyboards.com/)
+* Hardware Supported: OGRN PCB
+* Hardware Availability: https://alchemistkeyboards.com/projects/keyboards/ogr/
+
+Make example for this keyboard (after setting up your build environment):
+
+    make akb/ogrn:default
+
+Flashing example for this keyboard:
+
+    make akb/ogrn: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).
+
+## Bootloader
+
+Enter the bootloader in 3 ways:
+
+* **Bootmagic reset**: Hold down the key at (0,0) in the matrix (usually the top left key or Escape) and plug in the keyboard
+* **Physical reset button**: Briefly press the button on the back of the PCB - some may have pads you must short instead
+* **Keycode in layout**: Press the key mapped to `RESET` if it is available