Improve the "Making Good PRs" section

I often see PRs with misleading or vague titles. This is problematic, as the PR titles often end up being the commit titles, and commit titles are one of the most important tools we have when searching for historic changes. Bad titles impact maintainability.

Suggested edits:

• Enforce a strict title format
• Promote writing accurate and concise PR titles/descriptions

Perhaps the "Making Good PRs" section can be further promoted. Would it make sense to extract it and move it a level up in the doc hierarchy?

首先在開發者指南中找到「Making Good PRs」區段，並檢視周圍的文件階層。決定該區段應如何說明準確、簡潔的 pull request 標題與描述，以及它是否應位於更高層級。完成的標準是，指南及其位置清楚地反映 issue 建議的改進。