Demo and API docs

##<iron-autogrow-textarea>

iron-autogrow-textarea is an element containing a textarea that grows in height as more lines of input are entered. Unless an explicit height or the maxRows property is set, it will never scroll.

Example:

<iron-autogrow-textarea></iron-autogrow-textarea>

Styling

The following custom properties and mixins are available for styling:

Custom property	Description	Default
--iron-autogrow-textarea	Mixin applied to the textarea	{}
--iron-autogrow-textarea-placeholder	Mixin applied to the textarea placeholder	{}