Docs: links to section anchor returns 404

[lcjohnso]

Current behavior: Link in introduction (text = "rules defined in the workflow") has link URL = https://github.com/zooniverse/caesar/blob/master/docs/rules.md

Desired behavior: the link should instead lead to the internal page anchor found at https://zooniverse.github.io/caesar/#rules

Looks like the Slate docs is either misconfigured, or the link needs to be made explicit in the input markdown. Links should be fixed or removed.