fix

cmd/evening_detective_server/main.go

@@ -1,3 +1,4 @@
+// Package main starts the evening detective backend.
 package main
 
 import (
@@ -292,7 +293,7 @@ func main() {
 
 	docsHandler := v5emb.New("API", "/swagger/doc.json", "/docs/")
 	mainMux.Handle("/docs/", docsHandler)
-	mainMux.HandleFunc("/swagger/doc.json", func(w http.ResponseWriter, r *http.Request) {
+	mainMux.HandleFunc("/swagger/doc.json", func(w http.ResponseWriter, _ *http.Request) {
 		w.Header().Set("Content-Type", "application/json")
 		if _, err := w.Write(swaggerJSON); err != nil {
 			log.Printf("write swagger document: %v", err)