add already merged contributions to next whatsnew

A few users have made contributions that didn't get logged in a what's new document. Making an issue here so that we don't forget this. Probably easiest if I add the notes once #93 is merged. I believe that the following PRs need to mentioned:
- [x] #112
- [x] #111 
- [x] #109 
- [x] #108 
- [x] #103 
- [x] #122
