Turn the preview component into its own element

[rgreinho]

Issue Type

• Feature request

Expected Behavior

The preview component should be its own project and installable with bower.

Current Behavior

The component simply has its own file in the src directory of the project.

Possible Solution

1. Create a dedicated repository
2. Bootstrap the element creation with the Polymer CLI

[rgreinho]

This issue can be closed. Bower is deprecated, and we will focus on this when we believe we have good quality components that are reusable and we can share.