Remove useless subkind infer
Remove useless subkind infer

Co. #1971

> For the sigil part, I checked https://docs.perl6.org/js/search.js and lookup https://docs.perl6.org/language/variables.html#index-entry-%21%2525_%28sigil%29

> All sigil are X<>-ed manually. I'd like to remove 'sigil' from the very line, since its meaning is weird. If we want to make something searchable/indexed, use X<> as Pod6 spec.
stmuk/doc,dmaestro/doc,MasterDuke17/doc,tbrowder/doc,stmuk/doc,dmaestro/doc,jonathanstowe/doc,dmaestro/doc,perl6/doc,tbrowder/doc,tbrowder/doc,jonathanstowe/doc,perl6/doc,jonathanstowe/doc,MasterDuke17/doc,MasterDuke17/doc,stmuk/doc,perl6/doc,jonathanstowe/doc,perl6/doc,tbrowder/doc,stmuk/doc,jonathanstowe/doc,stmuk/doc,dmaestro/doc,MasterDuke17/doc,dmaestro/doc,perl6/doc