docs: Write triage docs for code intelligence

Created by: efritz

We need docs to help site-admins self-serve issues, as well as provide C(S)E teams a unified place to record past issues and look up solutions issues that may have occurred before.

The first draft of these docs should contain:

• A way to determine if the issue is related to code intelligence
• Solutions to outages we've seen before that may occur again (things that aren't currently fixed)
• A list of artifacts that a code intelligence engineer would need to diagnose a problem (depending on the symptoms)