Update skywriter-hat.md

src/en-GB/overlay/skywriter-hat.md

@@ -6,6 +6,15 @@ url: https://github.com/pimoroni/skywriter-hat
 github: https://github.com/pimoroni/skywriter-hat
 buy: http://shop.pimoroni.com/products/skywriter-hat
 description: A 3D positional and gesture sensor.
+install:
+  'apt':
+    - 'python-smbus'
+    - 'python3-smbus'
+    - 'python-dev'
+    - 'python3-dev'
+  'python':
+    - 'skywriter'
+  'examples': 'python/examples/'
 pincount: 40
 pin:
   '3':
@@ -22,4 +31,4 @@ pin:
 Skywriter HAT senses your finger's position above it in 3 dimensions, outputting an X, Y, Z axis
 which you can use in your Python scripts.
 
-It also recognises gestures, including swipes and more.
+It also recognises gestures, including swipes and more.