TR redesign

One of the AB's priority is to redesign the TR pages to make it more usable and help the users find the specifications they are looking for.

Here's a mockup of /TR with specific filters. One idea is to have a set of tags (managed by the community and fully documented in a github repository) we would use to mark each specification:

https://w3c.github.io/tr-pages/mockup1/

That page shows different kind of filters that can be combined together. Of course, we can imagine adding more filters like dates, etc.