add a macropad-dedicated readme file

Author: Neradoc

README-MACROPAD.md

@@ -0,0 +1,34 @@
+# Adafruit's Macropad and Keyboard Layouts
+
+When using the `adafruit_macropad` library with Adafruit's Macropad, you can setup the layout and keycode classes in the constructor with code like this.
+
+```py
+from adafruit_macropad import MacroPad
+
+from keyboard_layout_win_fr import KeyboardLayout
+from keycode_win_fr import Keycode
+
+macropad = MacroPad(
+    layout_class=KeyboardLayout,
+    keycode_class=Keycode,
+)
+```
+
+[See this file in the macropad library](https://github.com/adafruit/Adafruit_CircuitPython_MacroPad/blob/main/examples/macropad_keyboard_layout.py) for a full example script.
+
+## The Hotkeys Project
+
+For [the popular hotkeys project](https://learn.adafruit.com/macropad-hotkeys), not only will you have to update `code.py` with the change above, you also have to change the macros to use the keycodes setup in the macropad module instead of the `adafruit_hid` default keycode module.
+
+The `adafruit_macropad.keycodes` is a module-level variable that is setup with the value defined in the MacroPad class. When it's imported in the macros files it shares that value with the one defined in `code.py`.
+
+Replace:
+```py
+from adafruit_hid.keycode import Keycode
+```
+With:
+```py
+from adafruit_macropad import keycodes as Keycode
+```
+
+Note that some of the default macros might still use key names that are not available on your keyboard, or shortcuts that do not match the localized version of your applications. For example there is no `[` key on a French keyboard, if a shortcut uses it, it pust be changed to the correct shortcut for your application.

README.md

@@ -9,7 +9,10 @@ circup bundle-add Neradoc/Circuitpython_Keyboard_Layouts
 circup install keyboard_layout_win_fr keycode_win_fr
 ```
 
-NOTE: for pico-ducky users, [there's a dedicated guide](PICODUCKY.md).
+There's a couple of project-specific guides:
+
+- [How to use the layouts with Adafruit's Macropad and the **Hotkeys** project](README-MACROPAD.md).
+- [For pico-ducky users, there's a dedicated guide](PICODUCKY.md).
 
 ## Install your language