Update changelog.md

[btzr-io]

PR Checklist

Please check all that apply to this PR using "x":

• I have checked that this PR is not a duplicate of an existing PR (open, closed or merged)
• I added a line describing my change to CHANGELOG.md
• I have checked that this PR does not introduce a breaking change
• This PR introduces breaking changes and I have provided a detailed explanation below

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting)
• Refactoring (no functional changes)
• Documentation changes
• Other - Please describe:

Added missing changelog updates from previous and current contributions.

[jessopb]

💯