[css-spec-shortname-1] Wrap definition of @content-list in <dfn>

[OnkarRuikar]

• same as [css-namespaces-3] Wrap definition of @namespace in <dfn> #9402

Without the <dfn> tag the crowler is not able to pick the syntax.

There are 4-5 more docs in different modules that need such change. Should I create a separate PR for each module or include those changes here?

[OnkarRuikar]

I've linked the GitHub account to fix the ipr issue.

[w3cbot]

dontcallmedom marked as non substantive for IPR from ash-nazg.

[tabatkins]

Unfortunately this is wrong - it's a type, and so should be defined with angle brackets (and referenced with <<content-list>>). I'll go fix it properly, thanks for bringing it to my attention.

[OnkarRuikar]

I'll go fix it properly,

@tabatkins Thanks!

Also could you look into following issues:

1. <urange> type is not being extracted by reffy bot in webref. Don't know if the doc needs fixing or the reffy bot.
2. for background-blend-mode shouldn't this line be <pre class='propdef shorthand'> or use expanded version <<blend-mode>> | <a>plus-lighter</a> on line 299?