Add CHANGELOG.md

[masterleinad]

Step-3

[masterleinad]

I think we never really discussed what we want to include here. Is the autogenerated file good enough for us?

[aprokop]

The auto-generated changelog is a good start, but it looks noisy to me. Particularly, if the primary audience of the changelog file is users, there's no point in mentioning changes invisible to users. Things like code refactoring, updates in testing, fixing warnings, etc. So I would propose starting with auto-generated, but going through it with a human hand to trim it down, possibly with better descriptions.

[aprokop]

Couple other thoughts:

• I don't think we need changelog for all tags
  Specifically, the kokkos-* does not need changelog. Those tags serve a different purpose.
• I don't think we need authors in the CHANGELOG
• I think we don't need closed issues

[masterleinad]

I went through all items in the changelog to remove everything that is not user-facing/user-relevant (which is clearly opinionated).

[aprokop]

OK, I went through the CHANGELOG and cleaned things up. I introduced subsections for each release (New Features, Build Changes, Enhancements, Bug Fixes), and cleaned up the language for many pull requests to actually make sense from a user perspective.

[masterleinad]

@dalg24 @aprokop I went through the additional suggestions and applied most of them directly and the others with minor modifications please let me know if this looks good to you now.

[aprokop]

Overall, I'm fine with most suggestions. I would like to revert a couple, and have questions about few others.

[masterleinad]

@aprokop I saw that you pushed another commit addressing @dalg24's comments. Are both of you happy with the current status now? It looks OK to me.

[masterleinad]

Are we good to merge then?

[masterleinad]

@dalg24 Any final thoughts?

[masterleinad]

@Rombur Can you please take a look?