I have seen interest in solder auto-generating changelogs and also saw so many poor changelogs on the platform, that's why I wrote a little app. It just takes your existing solder pack and provides you with a full changelog between any two versions you wish.
http://isigiel.github.io/changelogger/ That's where you can try it out. Just paste any platform-api link which you can find here
To preload your pack use a link like the following one, stuff in  is optional, you can also just preload you url.
http://isigiel.github.io/changelogger/#/?url=<your api url>[&from=<build that's the changelogs base>&to=<build to compare to>]
I'm always open for suggestions and feedback
For the better changelog!
0.1 Better interface for selecting modpack builds (idea by @plowmanplow)
0.2 Modpack-makers: You can now preload a changelog you want (idea by @Jon_)