Add device repository homepage

[mjamescompton]

Summary

Add a page that has an overview of most popular devices, vendors and tags. Featured vendors and an explanation of what can be found in the device repository.

Why do we need this?

Making it easier to find devices you are looking for and improving SEO

What is already there? What do you see now?

The root page is identical to /devices which is redirected to the root. The root is just a list of all devices

What is missing? What do you want to see?

The page should include, repository description, search, featured devices, featured tags, featured vendors, Link to all devices.

How do you propose to implement this?

Design by @pierrephz, @mjamescompton will build

Can you do this yourself and submit a Pull Request?

yes