Update release instructions

[dbeatty10]

resolves N/A

Problem

When doing a release, there are steps that aren't enumerated explicitly, like:

• Creating a pull request with the relevant updates to the changelog
• How to update the release notes generated in the GitHub release into the format of our changelog

Solution

• Mention reformatting of the generated release notes
• Link to the changelog source code for reference
• Link to an example PR

Checklist

• This code is associated with an issue which has been triaged and accepted for development.
• I have read the contributing guide and understand what's expected of me
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• I have updated the README.md (if applicable)