readability: do not strip out content inside code & table elements

[nkanaev]

readability strips out code comments in https://2ality.com/2021/01/looping-over-arrays.html

I believe this has to do with .hljs-comment element classes. The solution could be to check for enclosing tags (taken from mozilla/readability):

func removeUnlikelyCandidates(document *goquery.Document) {
	document.Find("*").Not("html,body").Each(func(i int, s *goquery.Selection) {
		class, _ := s.Attr("class")
		id, _ := s.Attr("id")
		str := class + id
 
+		if s.Closest("code,table").Length() > 0 {
+			return
+		}

		if blacklistCandidatesRegexp.MatchString(str) || (unlikelyCandidatesRegexp.MatchString(str) && !okMaybeItsACandidateRegexp.MatchString(str)) {
			removeNodes(s)
		}
	})
}