Techniques H62 Using the ruby element has mentions to XHTML 1.1

[himorin]

Techniques H62 page on ruby has several reference to XHTML 1.1, like Applicability: XHTML 1.1 and HTML5, which is superseded spec.
(Also referring pages, like Understanding Success Criterion 3.1.6, have similar text.)

[alastc]

We have several other issues/PRs dealing with old references to XHTML, e.g. #2490

H62 doesn't seem to be covered, so I'll leave this open for now, but it might get closed as a duplicate in future.