New release note process

To make sure we have (1) have a nice list of release note changes, (2) we do not forget to add contributions in the release notes, I suggest to incrementally build the release notes with each PR. E.g., similar to the dev process in NumPy or scikit-learn.
Might as well call this 0.11.0 immediately. (I might prefer just 0.11, but I don't feel strongly about this.)