Support text-indent
text-indent is often used to hide text description of the icon e.g smashingmagazine.com:

<img width="817" alt="screen shot 2017-11-11 at 21 20 10" src="https://user-images.githubusercontent.com/985504/32693152-2297d558-c726-11e7-86f4-b6229b057055.png">

Currently, we are not hiding this text because text-indent is not supported.

