Add search box to grpc.io

[LisaFC]

What it says up there.

[LisaFC]

This should be simple enough: http://lcarey0-l.dub.corp.google.com:4000/grpc.github.io/docs/search/?q=streaming

Though now to make the search box look less weird. We also presumably don't want ads on it, so will need to sort out the premium version.

[LisaFC]

OK, we can get ad-free custom search if we're using Google for Non-Profits, I think we can probably sort that via CNCF, I'm investigating.

[sanjaypujare]

Any update on this? Search is needed on grpc.io

[April Kyle Nassi]

Closing this issue for now; we are migrating to a new site soon and can revisit search then if still needed.