All elements should appear in search results

I think that it would be helpful if, when you search for something like `textarea` the `paper-textarea` does not show up in the results. `paper-input` does but if you go to that page by chance then you have to look carefully to find the `paper-textarea` component. There are other examples like this such as `app-location`.
I think that search should display all elements, not just the top level ones.

It would also be nice to include these elements in the list of all elements. I learn a lot about an API just by looking through lists like these.