fix(cors): add CORS middleware

internal/server/http.go

@@ -10,7 +10,10 @@ import (
 	"tomatentum.net/svg-templater/pkg/svg"
 )
 
+var mux http.ServeMux
+
 func PrepareHTTP() {
+	mux = *http.NewServeMux()
 	registerAuthorizedFunc("/", func(w http.ResponseWriter, r *http.Request) {
 		fmt.Fprintln(w, "You are authorized!")
 	})
@@ -51,13 +54,14 @@ func PrepareHTTP() {
 
 func Start() {
 	log.Println("Starting http server on :3000")
-	if err := http.ListenAndServe(":3000", nil); err != nil {
+	handler := corsMiddleware(&mux)
+	if err := http.ListenAndServe(":3000", handler); err != nil {
 		panic(err)
 	}
 }
 
 func registerAuthorized(path string, handler http.Handler) {
-	http.HandleFunc(path, auth.AuthMiddleware(handler))
+	mux.HandleFunc(path, auth.AuthMiddleware(handler))
 	log.Println("Registered authorized handler for", path)
 }