open-source: add commitizen broken docs

[ttw225]

Summary

• Add a new open-source post: commitizen-broken-docs (bilingual content + related images).
• Reorganize open-source long-form content under posts/ and align the open-source hub structure.
• Improve open-source pages readability, including TOC behavior on article and list pages.

Why

• Keep open-source content discoverable from the hub while preserving a consistent post URL/content structure.
• Capture and document a real-world docs/rendering issue (Commitizen + Pygments) with actionable mitigation and follow-up.

Scope

• Content updates for open-source hub and related posts.
• Site structure adjustments for open-source content placement.
• Minor documentation/image naming cleanup.

[ttw225]

Good Good Good