training: more feedback
training: feedback from @arjclark
training: style
Merge pull request #355 from benfitzpatrick/training.more-feedback

rose training: additional feedback
Merge branch 'master' of github.com:metomi/rose into metomi-gh-pages
Merge branch 'master' into gh-pages
Merge branch 'gh-pages' of github.com:metomi/rose into gh-pages