KB article checker: Improve error messages on KB checker

[Blargian]

Summary

Error messages when the KB article fails are rather vague.

Makes a change to specifically output what the issue is and which KB article it is complaining about.

Checklist

• Delete items not relevant to your PR
• URL changes should add a redirect to the old URL via https://github.com/ClickHouse/clickhouse-docs/blob/main/docusaurus.config.js
• If adding a new integration page, also add an entry to the integrations list here: https://github.com/ClickHouse/clickhouse-docs/blob/main/docs/en/integrations/index.mdx