rails new -n a11yist -d sqlite3 --skip-action-mailbox --css bootstrap --js esbuild .

app/javascript/controllers/index.js

@@ -0,0 +1,8 @@
+// This file is auto-generated by ./bin/rails stimulus:manifest:update
+// Run that command whenever you add a new controller or create them with
+// ./bin/rails generate stimulus controllerName
+
+import { application } from "./application"
+
+import HelloController from "./hello_controller"
+application.register("hello", HelloController)