Claircore Documentation

Here's various codebase conventions that don't have dedicated pages:

• URLs URLs in code should be annotated with a //doc:url directive comment. See the the docs/injecturls.go file for documentation on how the preprocessor works. The list of keywords isn't an allowlist, so an invocation like the following should list the ones actually used in the documentation:

  git grep injecturls -- :/docs/*.md