Add favicon

Closes #8.

pkg/app/app.go

@@ -61,9 +61,13 @@ func (h *App) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	requestPath := r.URL.Path
 	var head string
 	head, r.URL.Path = shiftPath(r.URL.Path)
-	if head == "static" {
+	switch head {
+	case "static":
 		h.fileHandler.ServeHTTP(w, r)
-	} else {
+	case "favicon.ico":
+		r.URL.Path = requestPath
+		h.fileHandler.ServeHTTP(w, r)
+	default:
 		conn, err := h.db.Acquire(r.Context())
 		if err != nil {
 			panic(err)