Updating readme with npmcdn link and info about using the value prop

README.md

@@ -10,6 +10,12 @@
 $ npm install vue-input-autosize --save
 ```
 
+**or** include the UMD build, hosted by [npmcdn](https://npmcdn.com) in a `<script>` tag:
+
+```js
+<script src="//npmcdn.com/vue-input-autosize"></script>
+```
+
 ## Usage
 
 ```js
@@ -23,6 +29,9 @@ Vue.use(VueInputAutosize, { maxWidth: 500, minWidth: 20, comfortZone: 0 });
 
 `<input type='text' :value='msg' v-input-autosize />`
 
+### Why bind to `value` instead of using `v-model`?
+Currently, there's no easy way to track changes to a `v-model` value from a directive. However, since the `value` property of a text field controls its content, and is also a valid parameter to watch for updates from the directive, we can dynamically bind to that instead.
+
 ## License
 
 MIT © [Collin Henderson](https://github.com/syropian)