Update README.md

Author: AdaRoseCannon

README.md

@@ -3,3 +3,30 @@
 This is weird and terrible.
 
 We use a THREE.js Canvas Renderer in a paint worklet!!
+
+The worklet code is in [main.js](https://github.com/AdaRoseCannon/three-paint/blob/master/src/main.js)
+
+Use `npm run start` to build it.
+
+Use it in HTML like so:
+
+
+```html
+
+<style>
+  .some-el {
+    --rotate-x: 0;
+    --rotate-y: 0;
+    --rotate-z: 0;
+  
+    background-color: lavenderblush;
+    background-image: paint(three);
+  }
+</style>
+
+<script>
+  CSS.paintWorklet.addModule('./dist/bundle.js');
+<script>
+```
+
+![Preview](https://pbs.twimg.com/media/Dh1Zk_qX0AAf10P.jpg)