use cache control on static

src/index.ts

@@ -4,12 +4,19 @@ import app from "./app.js";
 
 const site = express();
 
+const maxAge = 1000 * 60 * 60 * 24 * 7;
+
 nunjucks.configure("templates", {
   autoescape: true,
   express: site,
 });
 
-site.use(express.static("."));
+site.use(
+  express.static(".", {
+    maxAge: maxAge,
+    immutable: true,
+  })
+);
 
 site.get("/", app.index);