add: logparser v5 shared record

logparser/v5/pipe/groupers.go

@@ -12,10 +12,10 @@ package pipe
 // For example: It returns the page field as well.
 // Exercise: Write a solution that removes the unnecessary data.
 func DomainGrouper(r Record) string {
-	return r.Domain
+	return r.domain
 }
 
 // Page groups records by page.
 func Page(r Record) string {
-	return r.Domain + r.Page
+	return r.domain + r.page
 }