rose-rug-suites: Split rose rug suites

Closes #1452

This splits the rose-rug-suites.html file into rose-rug-suites-I.html and rose-rug-suites-II.html.

Changes themselves can be found in the first commit. Second commit is run through tidy (which has reorganised some of the existing text as well as my additions).
Probably worth mentioning `suites II` at this point as well.