Docs updates: add installing, advanced recipes, remote gpio and remote recipes - wip

docs/examples/multi_room_motion_alert.py

@@ -0,0 +1,14 @@
+from gpiozero import LEDBoard, MotionSensor
+from gpiozero.pins.pigpio import PiGPIOPin
+from signal import pause
+
+ips = ['192.168.1.3', '192.168.1.4', '192.168.1.5', '192.168.1.6']
+remote_pins = [PiGPIOPin(17, host=ip) for ip in ips]
+
+leds = LEDBoard(2, 3, 4, 5)  # leds on this pi
+sensors = [MotionSensor(pin) for pin in remote_pins]  # motion sensors on other pis
+
+for led, sensor in zip(leds, sensors):
+    led.source = sensor.values
+
+pause()