Use a local copy of jquery so that the docs work in China, and offline too.

prompted by https://github.com/docker/docker-index/pull/1499

It also looks like the jquery CDN is slow - this may help with the initial load menu freeze

Docker-DCO-1.1-Signed-off-by: Sven Dowideit <SvenDowideit@docker.com> (github: SvenDowideit)