Minor PR template enhancement

[Genyus]

Description

Makes a small change to instructions

Motivation and Context

Need to test Slack notification formatting

How has this been tested?

Can't be tested before merging

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Test addition/modification (change that adds or modifies tests)
• Exercise solution (implementation of an exercise solution)
• Documentation (change to documentation)
• Refactoring (improvement to code structure without changing functionality)

Checklist:

• I have read the CONTRIBUTING document.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.