training: rewrite retry tutorial
training: remove header
training: dice
training: implement feedback
Happy new year.
training: fix
Merge pull request #328 from matthewrmshin/happy-new-year

Happy new year.
Merge pull request #315 from benfitzpatrick/training.retry-tutorial

Training: rewrite retries tutorial
Merge branch 'master' of github.com:metomi/rose into metomi-gh-pages