Turn Atlas into page on Tor Metrics

We briefly discussed this before, but I didn't find a ticket for it, so I made this one.

Let's consider turning Atlas into a page on Tor Metrics. It could live under "Home >> Services >> Atlas".

From a technical perspective I think we could add Atlas as Git submodule and copy its index.html into a JSP, so that we can include the Tor Metrics banner and footer. And we'd copy over all required JS files.

It would certainly help to get rid of Atlas' navbar and footer and make sure that it works well with Metrics' style file.