Add promo for The Grid

##### Large screens
![screen shot 2014-10-16 at 18 29 06](https://cloud.githubusercontent.com/assets/84700/4667279/382f8676-555b-11e4-929f-19b9cf8e4267.png)
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##### Small screens:
![screen shot 2014-10-16 at 18 29 31](https://cloud.githubusercontent.com/assets/84700/4667280/39eb33e8-555b-11e4-9281-b0eefbcc2c2d.png)
***
##### Secondary pages
![screen shot 2014-10-16 at 18 38 37](https://cloud.githubusercontent.com/assets/84700/4667281/49e4b0a8-555b-11e4-8c41-e61c80fc5b94.png)