Fast trigram based code search

GitHub Code Search has too many quirks compared to the zoekt powered alternatives (cs.android.com, cs.bazel.build) which feel far more intuitive.

I wish Microsoft would invest more in improving it - especially since Sourcegraph can't search private repositories, leaving GitHub's tool as the only real option for many codebases.

more background: https://sourcegraph.com/blog/zoekt-creating-internal-tools-a...