feat: Investigate having localhost search

"Ideally we should be able to fun this entire docs system with forc locally, like `forc doc --docs` or something like that then it would run the doc harness on a server, and it should work with search." - Nick

Start by examining how the docs system and its doc harness are currently run locally, then investigate the proposed `forc doc --docs` entry point. Done means the full docs system can run locally through a command like this, with the doc harness serving the site and search working.

Written by the indexing model from the issue text.