Why do some pages don't have titles in the deployed site?

Consider the following pages in https://git.github.io/ :

• https://git.github.io/Hacking-Git/
• https://git.github.io/General-Microproject-Information/

Observe that even though they have a proper title mentioned in the corresponding Markdown files, the titles don't appear in the body of the text. It is only visible in the link and the title of the tab in the browser. Is there a particular reason for this? Or is there no particular reason for this?

將對應的 Markdown 檔案與已部署的 Hacking-Git 和 General-Microproject-Information 頁面進行比較，然後追蹤它們的標題是如何呈現的。確認缺少的本文標題是否是有意為之，或找出阻止它們顯示的網站行為；當該行為獲得解釋，或兩個頁面都一致地顯示其標題時，即視為完成。