Add other repos in bazelbuild to code search

Hi folks,

I was wondering if we could setup code search to support the like of rules_go, rules_rust and rules_docker etc...

These repos are primarily written in go/rust which are the languages that Kythe already have a functioning extractor for.

Even without Kythe indexing, it would be nice just to get repos such as rules_python into https://cs.opensource.google/bazel so that we can search using regex.

Cheers.

The issue names no files, tests, or entry points. Start by finding the existing code-search configuration for bazelbuild repositories and comparing how rules_go, rules_rust, rules_docker, and rules_python would be included. Done means the requested repositories are searchable, including regex search even where Kythe indexing is unavailable.

Written by the indexing model from the issue text.