refactor: specify all commits

The reason why I wrote `match_commits` is because when you have a lot of commits, the diff that `match_array` outputs is very hard to look at. I have wasted hours digging through them, copy-and-pasting into TextEdit to reformat them, and make sense of them. The intent of `match_commits` is to provide a more human-readable diff that tries to give a higher-level perspective by
* printing commits more concise and meaningful
* showing which commits are missing, and which are unexpected

If you have an idea on how do this better I'm all ears, but I feel quite strongly to keep this helper around.