Option to Resolve Meeseeks Backports

[blink1073]

Description / Summary

I would like to be able to see the original PR in my changelog when it is a Meeseeks backport.

Value / benefit

Readers can save some confusion and an extra click to find the original change, as well as being easier to read.

Implementation details

This could be an option passed to the CLI. We currently automatically do this in Jupyter Releaser.

Tasks to complete

• [ ] Decide whether to do this and what to call the CLI flag
• [ ] Port the logic from Jupyter Releaser