Description

Removes HTML comments in favor of markdown "comments" of the form:
[NOTE]: # ( ..... )

This will help with non-web views that actually render HTML comments as plain text (Fasthub, GitKraken Glo, etc.)

Streamlined the PR template a little and updated the wording of the contributing document.

Motivation and context

Avoiding doing school work 😁

Types of changes

• ✅ Documentation

Checklist:

• ✅ I have read the CONTRIBUTING document. [REQUIRED]
• ✅ My code follows the code style of this project. [REQUIRED]
• ✅ All new and existing tests passed. [REQUIRED]
• ✅ I have compiled and verified my code with -DWITH_ASAN=ON. [REQUIRED]
• ✅ My change requires a change to the documentation and I have updated it accordingly.