WIP Relay editing UI

app/javascript/controllers/relay_list_editor_controller.js

@@ -0,0 +1,17 @@
+import { Controller } from "@hotwired/stimulus"
+
+export default class extends Controller {
+  static targets = [ "list", "template" ]
+
+  add (event) {
+    event.preventDefault()
+    const row = this.templateTarget.content.cloneNode(true)
+    this.listTarget.appendChild(row)
+  }
+
+  remove (event) {
+    event.preventDefault()
+    const row = event.target.closest("li")
+    row.remove()
+  }
+}