Add allowed hosts

Co-authored-by: Copilot <copilot@github.com>

vite.config.ts

@@ -5,5 +5,6 @@ export default defineConfig({
   plugins: [react()],
   preview: {
     port: 8089,
+    allowedHosts: ["runosaari.fi", "www.runosaari.fi"],
   },
 });