Update rendering of COSE examples

[decentralgabe]

          there is a build error pertaining to the EDN lib generating HTML in a way that breaks the W3C lint checker

"file:/home/runner/work/vc-jose-cose/vc-jose-cose.w3c/index.html":1666.3-1666.9: error: Element “style” not allowed as child of element “section” in this context. (Suppressing further errors from this subtree.)
"file:/home/runner/work/vc-jose-cose/vc-jose-cose.w3c/index.html":1684.26-1684.29: error: Element “dl” not allowed as child of element “dl” in this context. (Suppressing further errors from this subtree.)
"file:/home/runner/work/vc-jose-cose/vc-jose-cose.w3c/index.html":1691.64-1691.67: error: Element “dl” not allowed as child of element “dl” in this context. (Suppressing further errors from this subtree.)
"file:/home/runner/work/vc-jose-cose/vc-jose-cose.w3c/index.html":1690.5-1690.36: info warning: Section lacks heading. Consider using “h2”-“h6” elements to add identifying headings to all sections, or else use a “div” element instead for any cases where no heading is needed.

I am going to merge as-is and consider making the examples statically generated in a follow-up issue.

Originally posted by @decentralgabe in #258 (comment)