Add documentation for the LEDControl plugin (#1405)

* Get started with LEDControl documentation
* Add documentation for a number of methods

Signed-off-by: Evy Bongers <evy@evybongers.nl>

plugins/Kaleidoscope-LEDControl/README.md

@@ -1,6 +1,125 @@
 # Kaleidoscope-LEDControl
 
 This is a plugin for [Kaleidoscope][fw], for controlling the LEDs, and LED
-effects.
+effects. It is also a building block for plugins that control LEDs.
 
  [fw]: https://github.com/keyboardio/Kaleidoscope
+
+## Using the extension
+
+## Plugin methods
+
+### `.next_mode(void)`
+
+> Activates the next LED mode. Cycles to the first LED mode if the current LED
+> mode is the last one.
+
+### `.prev_mode(void)`
+
+> Activates the previous LED mode. Cycles to the last LED mode if the current
+> LED mode is the first one.
+
+### `.get_mode()`
+
+> Returns the current LED mode.
+
+### `.get_mode<typename>()`
+
+
+### `.set_mode(uint8_t mode_id)`
+
+> Activates a LED mode by its index in the firmware. If the index exceeds the
+> numer of led modes, the method returns early.
+
+### `.get_mode_index()`
+
+> Returns the index of the currently active LED mode.
+
+### `.refreshAll()`
+
+> If the hardware has LEDs and LEDs are enabled, turn all LEDs off and then
+> trigger the current LED mode to refresh.
+
+### `.setCrgbAt(uint8_t led_index, cRGB crgb)`
+
+> Sets the specified LED to the provided color.
+
+### `.setCrgbAt(KeyAddr key_addr, cRGB color)`
+
+> Sets the LED for the specified key to the provided color.
+
+### `.getCrgbAt(uint8_t led_index)`
+
+> Get the LED color of the specified LED.
+
+### `.getCrgbAt(KeyAddr key_addr)`
+
+> Get the LED color of the LED for the specified key.
+
+### `.syncLeds(void)`
+
+> Force an update of all LEDs.
+
+### `.set_all_leds_to(uint8_t r, uint8_t g, uint8_t b)`
+
+> Set all LEDs using the provided rgb values.
+
+### `.set_all_leds_to(cRGB color)`
+
+> Set all LEDs to the specified color.
+
+### `.setSyncInterval(uint8_t interval)`
+
+> Set the interval at which the LEDs should sync, in milliseconds.
+>
+> Note: LED updates are considered on each cycle of the runtime. Because of
+> that, the interval effectively means that _at least_ `interval` milliseconds
+> has passed before LEDs are synced.
+
+### `.setBrightness(uint8_t brightness)`
+
+> Set the brightness for all LEDs.
+
+### `.getBrightness()`
+
+> Returns the current brightness of the LEDs as a uint8_t.
+
+### `.onSetup()`
+
+> See [[event-handler-hooks]]
+
+### `.setup(void)`
+
+
+### `.onKeyEvent(KeyEvent &event)`
+
+> See [[event-handler-hooks]]
+
+### `.afterEachCycle()`
+
+> See [[event-handler-hooks]]
+
+### `.update(void)`
+
+> Triggers the currently active LED mode to update. It is up to the LED mode to
+> handle this correctly.
+
+### `.refreshAt(KeyAddr key_addr)`
+
+> Triggers the currently active LED mode to refresh the LED at the specified key
+> address.
+
+### `.activate(LEDModeInterface *plugin)`
+
+
+### `.disable()`
+
+> Turn off all LEDs and disables updating LEDs
+
+### `.enable()`
+
+> Enables updating LEDs and calls `refreshAll()`
+
+### `.isEnabled()`
+
+> Returns a bool value reflecting whether LEDs are currently enabled.