Cleaned up scheme tags for proper validation

Nesting `itemprop` attributes can cause Google's validator to go on the fritz.

`name` and `description` for example, shouldn't be inside `itemprop="offers"`

[Check the validator here](http://www.google.com/webmasters/tools/richsnippets?q=https%3A%2F%2Ftimber-demo.myshopify.com%2Fproducts%2Fwomens-long-cardigan)