These devs aren't keeping up a changelog here at GoG, but they are keeping a proper one on Github:
https://github.com/endless-sky/endless-sky/blob/v0.10.12/changelog

And they have a blog too that they're still keeping up with posts about new patches and other topics::
https://endless-sky.github.io/blog.html

I'm updating the changelog on the GoG backend when I push updates. I'm not sure why the patch notes section in GoG Galaxy for the game only shows 0.10.6 and 0.10.8. ¯\_(ツ)_/¯