Add readme

README.md

@@ -1 +1,46 @@
-# image-diff
+# Image Diff
+
+Real-time image diffing in the browser, powered by WebGL.
+
+## Installing
+
+```shell
+npm install @rolemodel/image-diff
+```
+
+or
+
+```shell
+yarn add @rolemodel/image-diff
+```
+
+## Usage
+
+```javascript
+import ImageDiff from "@rolemodel/image-diff"
+
+const originalImage = document.getElementById('base-image')
+const newImage = document.getElementById('new-image')
+const imageDiff = new ImageDiff(originalImage, newImage)
+
+const result = imageDiff.update({
+  diffColor: { r: 1, g: 0, b: 0 },
+  diffThreshold: 0.2,
+  backgroundAlpha: 1.0
+})
+
+// result is a canvas element
+document.body.appendChild(result)
+
+imageDiff.dispose()
+```
+
+Calling `update()` again will re-render the diff. Make sure to call `dispose()` to clean up WebGL resources.
+
+## Acknowledgments
+
+**image-diff** is [MIT-licensed](LICENSE), open-source software from [RoleModel Software][rms]. It was initially based on [pixelmatch](https://github.com/mapbox/pixelmatch), using a similar algorithm ported to WebGL.
+
+[RoleModel Software][rms] is a world-class, collaborative software development team dedicated to delivering the highest quality custom web and mobile software solutions while cultivating a work environment where community, family, learning, and mentoring flourish.
+
+[rms]: https://rolemodelsoftware.com/