Fix `forbid-docs-links` errors
Created by: umpox
Description
Rule enabled in this PR: https://github.com/sourcegraph/sourcegraph/pull/32205
Slack context: https://sourcegraph.slack.com/archives/C0C324C91/p1641855680027300
We should be using /help in place of docs.sourcegraph.com for links in-product. /help will automatically version docs in the URL to serve a cached version-correct docsite
Test plan
Run eslint
- expect no errors