This discourages depending on all of a component's extensions and aligns our targets more closely with how we expect them to be imported and depended upon. This is a breaking change. Pivotal story: https://www.pivotaltracker.com/story/show/157118721
* Generate all themer documentation. * Fix Snackbar vars. * Fix textfields vars. * Fix link. * Fix bottom app bar vars. * Fix more vars. * Add home page links. * Fix typos. * Fix more links. * Add ink. * Tabs. * Cleanup.