Adding more items in PR checklists.

[yingsu00]

Description

Adding more items in PR checklists. Correct the bullet point indentations.

Motivation and Context

To help PR review process

Impact

N/A

Test Plan

Showed up correctly in preview mode

Contributor checklist

• Please make sure your submission complies with our contributing guide, in particular code style and commit standards.
• PR description addresses the issue accurately and concisely. If the change is non-trivial, a GitHub Issue is referenced.
• Documented new properties (with its default value), SQL syntax, functions, or other functionality.
• If release notes are required, they follow the release notes guidelines.
• Adequate tests were added if applicable.
• CI passed.

Release Notes

== NO RELEASE NOTE ==