[Keyboard] add Radialex (#14949)

Co-authored-by: Drashna Jaelre <drashna@live.com>
Co-authored-by: Ryan <fauxpark@gmail.com>
Co-authored-by: takashicompany <takashicompany@TMPB2021.local>

keyboards/takashicompany/radialex/readme.md

@@ -0,0 +1,31 @@
+# Radialex
+
+![Radialex](https://github.com/takashicompany/radialex/blob/master/images/qmk.jpg?raw=true)
+
+40% larger keyboard.  
+The radial key layout allows you to place your hand in a natural position and move your fingers the shortest distance to type.  
+Your iconic keys and keycaps can be placed in the center of the keyboard.  
+It is possible to make it shine with LED backlighting.  
+The keyswitches can also be replaced with MX sockets.  
+
+* Keyboard Maintainer: [takashicompany](https://github.com/yourusername)
+* Hardware Supported: PCB, Pro Micro
+* Hardware Availability: https://github.com/takashicompany/radialex
+
+Make example for this keyboard (after setting up your build environment):
+
+    make takashicompany/radialex:default
+
+Flashing example for this keyboard:
+
+    make takashicompany/radialex: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