html_tag.go
func (e *htmlTag) IsBlockElement() bool {
	if inline, found := inlineElements[e.tagName]; found {
		return !inline
	} else {
		return true
	}
}
func (e *htmlTag) IsBlockElement() bool {
	if inline, found := inlineElements[e.tagName]; found {
		return !inline
	} else {
		return true
	}
}
// true if the element is inline one