Add small blink example as bootloader payload test

blink/bootloader.hpp

@@ -0,0 +1,24 @@
+#pragma once
+
+class Bootloader {
+  public:
+	template <typename Fn>
+	static inline void init(Fn callback)
+	{
+		if (handleReset()) {
+			callback();
+			call();
+		}
+	}
+
+	static inline void enter()
+	{
+		reset();
+	}
+
+  private:
+	static bool handleReset();
+	static void reset();
+	static bool check();
+	static void call();
+};