add demo

Add my demo.
https://observablehq.com/@brakdag/conway-game-of-life-gpu-js

README.md

@@ -141,6 +141,7 @@ GPU.js in the wild, all around the net.  Add yours here!
 * [Shaded relief with gpujs and d3js](https://observablehq.com/@rveciana/shaded-relief-with-gpujs-and-d3js/2)
 * [Caesar Cipher GPU.js Example](https://observablehq.com/@robertleeplummerjr/caesar-cipher-gpu-js-example)
 * [Matrix Multiplication GPU.js + Angular Example](https://ng-gpu.surge.sh/)
+* [Conway's game of life](https://observablehq.com/@brakdag/conway-game-of-life-gpu-js)
 
 ## Installation
 On Linux, ensure you have the correct header files installed: `sudo apt install mesa-common-dev libxi-dev` (adjust for your distribution)