[scikit-image] scikit-learn governance document proposal

Hi Everyone, Andy Mueller just submitted a pull request outlining a scikit-learn governance document. Since I would like to involve everyone in the adoption of a similar document for scikit-image, I thought I would bring it to your attention so that you can start to stew on things you might like or dislike about it. (I have yet to stew on it but, broadly, it seems like a good fit for us too. =) https://github.com/scikit-learn/scikit-learn/pull/12878 Juan.