feat(logs): add logs for list handler

main.go

@@ -149,6 +149,7 @@ func main() {
 
 	mux := http.NewServeMux()
 	mux.HandleFunc("/list", func(w http.ResponseWriter, r *http.Request) {
+		log.Printf("request /list from %s [%s %s]", r.RemoteAddr, r.Method, r.UserAgent())
 		links := agg.List()
 		w.Header().Set("Content-Type", "text/plain; charset=utf-8")
 		for i, link := range links {
@@ -157,6 +158,7 @@ func main() {
 			}
 			_, _ = w.Write([]byte(link))
 		}
+		log.Printf("response /list to %s: %d links", r.RemoteAddr, len(links))
 	})
 
 	server := &http.Server{