Be more explicit in release changelogs about breaking changes

[FilippoBonazziSUSE]

Hi, I am one of the openSUSE maintainers of Waybar and openSUSEway.

I recently realized that Waybar 0.9.18 significantly overhauled the clock module (much nicer now), leading to my tooltip calendar configuration being broken. A similar calendar configuration is used in openSUSEway, leading to all users of openSUSEway to have their calendar kind of broken.

There was nothing in the 0.9.18 release changelog that made me think of breaking changes. To be fair, I didn't notice the broken calendar when I packaged Waybar 0.9.18 for openSUSE, and I only noticed it on my machine a few weeks later.

It would be nice if breaking changes would be described explicitly in a section of the changelog, so that downstream maintainers and distributors could take action immediately and avoid breaking the user experience.

Thank you for all the awesome work.