doc: use Swiftype search
Created by: bobheadxi
Integrate Swiftype for https://docs.sourcegraph.com at https://app.swiftype.com/engines/sourcegraph-docs, similar to what is available in the handbook (https://github.com/sourcegraph/about/pull/3153)
This gives us some pretty exciting features on the backend:
We can also make regular reports, like is currently done for the handbook: https://sourcegraph.slack.com/archives/C021KFCA5MF/p1627303929083700
On the frontend, it mostly integrates quite nicely into the existing UI. NGL it don't look great in but I fiddled for about an hour and I think this is good enough, CSS is too hard. I kept the /search
page which I like better than the popup (quite laggy on the handbook):