samples: simpleblinker rpi example

does not cleanup up after itself, but is concise

samples/.gitignore

@@ -17,6 +17,7 @@ pwm
 servo
 servobbb
 servoblaster
+simpleblinker
 tmp006
 us020
 watersensor

samples/simpleblinker.go

@@ -0,0 +1,20 @@
+// +build ignore
+
+// Simple LED blinker, works OOTB on a RPi. However, it does not clean up
+// after itself. So might leave the LED On. The RPi is not harmed though.
+
+package main
+
+import (
+	"time"
+
+	"github.com/kidoman/embd"
+	_ "github.com/kidoman/embd/host/rpi"
+)
+
+func main() {
+	for {
+		embd.LEDToggle(0)
+		time.Sleep(250 * time.Millisecond)
+	}
+}