Added documentation for async buttons.

Author: SamGraber

README.md

@@ -16,7 +16,7 @@ Angular components that can be added to an application.
 * [autosaveDialogFooter]()
 * [busy]()
 * [button](/source/components/button/button.md)
-* [buttonAsync]()
+* [buttonAsync](/source/components/buttonAsync/buttonAsync.md)
 * [buttonLink]()
 * [buttonToggle]()
 * [cardContainer]()

source/components/buttonAsync/buttonAsync.md

@@ -0,0 +1,52 @@
+# Button Async
+Button for triggering asynchronous operations. The async button handles showing a spinner until a promise is resolved. For simple actions, use [button](/source/components/button/button.md) instead.
+
+### Usage
+```
+<rl-button-async action="" size="" type="" ng-disabled="" right-aligned="" busy=""> ... </rl-button>
+```
+### Options
+
+#### `action`
+
+The expression in the **action** will be triggered when the button is clicked. If the action returns a promise, the button will show a spinner until the promise resolves. If the action returns true, the button will show a spinner until told to do otherwise via the busy option.
+
+#### `busy`
+
+This option allows you to show/hide the spinner via a binding. This is useful in cases where simply returning a promise from the action isn't sufficient.
+
+#### `right-aligned`
+
+Specifies if the button is within a right aligned context. Defaults to `false`. This is used by the button to determine which side the spinner should show on.
+
+#### `size`
+
+This will set the **size** of the button. We use the following sizes: `xs`, `sm`, `md`, `lg`. This option is applied to the button's class attribute and prefixed with `btn-`.
+
+Example: `size="lg"` will ouput `class="btn-lg"`.
+
+#### `type`
+
+This option sets the button's **visual type**. This option defaults to `default`. We use the following types: `primary`, `success`, `danger`, `info`, `warning`, `link`. This option is applied to the button's class attribute and prefixed with `btn-`.
+
+Example: `type="danger"` will output `class="btn-danger"`.
+
+
+#### [`ng-disabled`](https://docs.angularjs.org/api/ng/directive/ngDisabled)
+
+This option will set `disabled` on the button if the [expression](https://docs.angularjs.org/guide/expression) inside it is truthy.
+
+Example: `ng-disabled="true"` will output `<button disabled> ... </button>`
+
+### Full Example
+An async button with an **action**, **size**, **type**, **right-align** and **busy**.
+```
+<rl-button action="button.click()" size="lg" type="danger" ng-disabled="false" right-aligned="true" busy="true"> ... </rl-button>
+```
+Output:
+```
+<button type="button" class="btn btn-lg btn-danger" ng-click="button.click()" disabled>
+	<rl-busy loading="true"></rl-busy>
+	...
+</button>
+```