[Improve Existing Best Practice Guide]: CHANGELOG should be more about high-level news / updates for a broader audience

[riverma]

Checked for duplicates

Yes - I've already checked

Best Practice Guide Category

Documentation

Best practice guide URL

https://nasa-ammos.github.io/slim/docs/guides/documentation/change-log/

Describe the improvement

We've seen the evolution of tools like GitHub Releases, and we'd like to recommend two options:

1. Remove the need for a CHANGELOG.md given the fact of strong overlap with GitHub Releases
2. Morph CHANGELOG.md to point to specific release information elsewhere, but focus on high-level changes for end-users

[yunks128]

I updated CHANGELOG.md focusing on high-level changes for end users and pointing to the release link (following the option 2): #174

@hookhua Do you have any preference between options 1 and 2? Thanks for your suggestion!