Simplify instructions in pull request template

[josh-wong]

Description

This PR simplifies the instructions in the pull request template.

Related issues and/or PRs

N/A

Changes made

• Revised instructions int he pull request template.

Checklist

The following is a best-effort checklist. If any items in this checklist are not applicable to this PR, add N/A after each item.

Documentation

• [x] I have updated the side navigation as necessary. N/A
• [x] I have updated the documentation to reflect the changes. N/A
• [x] I have documented or updated any remaining open issues linked to this PR in GitHub, Obsidian, etc. N/A

Build, deploy, and test

• [x] I have merged and published any dependent changes in other PRs. N/A
• [x] I have commented my code, particularly in hard-to-understand areas. N/A
• [x] I have checked that my changes look as expected on a locally built version of the docs site. N/A
• [x] My changes generate no new warnings. N/A