add rgb check and example

examples/README.md

@@ -9,6 +9,8 @@ Each example is its own Cargo package.
 - `button-input` - poll the center button on `PA8`, mirror state to `PC13`, log transitions
 - `embassy-blinky` - minimal Embassy executor and async blink
 - `embassy-button` - minimal Embassy polling loop for the center button on `PA8`
+- `embassy-rgb-check` - simple RGB on/off check on `PA1`/`PA2`/`PA3`
+- `embassy-rgb` - async RGB PWM animation on `PA1`/`PA2`/`PA3`
 
 ## Build One Example
 
@@ -18,6 +20,8 @@ just build-timer
 just build-button
 just build-embassy-blinky
 just build-embassy-button
+just build-embassy-rgb
+just build-embassy-rgb-check
 ```
 
 ## Flash One Example
@@ -28,6 +32,8 @@ just flash-timer
 just flash-button
 just flash-embassy-blinky
 just flash-embassy-button
+just flash-embassy-rgb
+just flash-embassy-rgb-check
 ```
 
 ## Run With Logs
@@ -35,4 +41,6 @@ just flash-embassy-button
 ```bash
 just run-blinky
 just run-embassy-blinky
+just run-embassy-rgb
+just run-embassy-rgb-check
 ```