* Mention changelog requirements in CONTRIBUTING
* Refer to CONTRIBUTING in changelog workflow
* Clarify when changelog entries are necessary
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Co-authored-by: Martin Nordholts <martin.nordholts@codetale.se>
* CONTRIBUTING.md: Encourage regression tests
* Add colon before listing pros of regression tests
Co-authored-by: Keith Hall <keith-hall@users.noreply.github.com>