Resolve "Refactor CHANGELOG.md before v2.0 release"

What does this MR do?

Merge related items in the CHANGELOG.md and reformat according to Markdown linter.

Is there something that needs to be double checked?

No.

Can this MR be accepted?

• Added/Updated CHANGELOG.md
• [ ] Pipeline passing
• Squash option set
• Delete branch option set
• [ ] Added entry to CHANGELOG.md

Assignee: If the Squash option is set, check/update the commit message right before merging!

Related issues

Closes #190 (closed)