Fix markdown format in gang scheduling doc

There's 2 error in Chinese document.

The first one has a missing backtick at the end, and the second one has a misplaced backtick.

1. https://github.com/targetoee/yunikorn-site/blob/bf0f2a5793eb31732793fd636d22baa6f99bef18/i18n/zh-cn/docusaurus-plugin-content-docs/current/user_guide/gang_scheduling.md?plain=1#L124
2. https://github.com/targetoee/yunikorn-site/blob/bf0f2a5793eb31732793fd636d22baa6f99bef18/i18n/zh-cn/docusaurus-plugin-content-docs/current/user_guide/gang_scheduling.md?plain=1#L235