Make doc links more accessible

[ramaraochavali]

https://www.envoyproxy.io/docs lists stable releases, Latest and followed by archived releases. This some times is inconvenient for folks who want to look at latest docs and they have to scroll down every time.

Can we organize in such a way that latest shows on top and below that there are columns one for stable releases and one for archived releases - so that it is easy to access without scrolling much?

[phlax]

we have a new theme in dev which should improve the navigation to docs