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

docs/examples/led_remote_3.py

@@ -0,0 +1,14 @@
+from gpiozero import LED
+from gpiozero.pins.pigpio import PiGPIOPin
+from time import sleep
+
+led_1 = LED(17)  # local pin
+led_2 = LED(PiGPIOPin(17, host='192.168.1.3'))  # remote pin
+
+while True:
+    led_1.on()
+    led_2.off()
+    sleep(1)
+    led_1.off()
+    led_2.on()
+    sleep(1)