Render error pages as HTML

handlers/not-found.ts

@@ -0,0 +1,10 @@
+import { Context } from "@oak/oak";
+import { errorPageHtml } from "../html.ts";
+
+const notFoundHandler = function (ctx: Context) {
+  const html = errorPageHtml(404, "Not found");
+  ctx.response.body = html;
+  ctx.response.status = 404;
+};
+
+export default notFoundHandler;