Expand basic example in readme

README.rst

@@ -15,10 +15,25 @@ The latest release is 1.0 released on 16th November 2015.
 About
 =====
 
-With very little code, you can quickly get going connecting your physical
-components together::
+Component interfaces are provided to allow a frictionless way to get started
+with physical computing::
+
+    from gpiozero import LED
+    from time import sleep
+
+    led = LED(2)
+
+    while True:
+        led.on()
+        sleep(1)
+        led.off()
+        sleep(1)
+
+With very little code, you can quickly get going connecting your components
+together::
 
     from gpiozero import LED, Button
+    from signal import pause
 
     led = LED(2)
     button = Button(3)
@@ -26,6 +41,8 @@ components together::
     button.when_pressed = led.on
     button.when_released = led.off
 
+    pause()
+
 The library includes interfaces to many simple everyday components, as well as
 some more complex things like sensors, analogue-to-digital converters, full
 colour LEDs, robotics kits and more.