Avoid attempting to link to a third-party replacement rule for a deprecated rule

[bmish]

When a rule is deprecated and specifies a third-party rule as its replacement (meta.replacedBy: ['foo/some-external-rule']), we should avoid attempting to link to it as if it's one of our own rules, as this will result in a broken link. Since we won't know the correct path to it, we'll have to avoid linking to it for now.

Perhaps meta.replacedBy should allow specifying the URL to the replacement rule. This is related to jsx-eslint/eslint-plugin-react#3469 (comment).