allow to invite party

app/javascript/elements/checkbox_group.js

@@ -0,0 +1,15 @@
+export default class extends HTMLElement {
+  connectedCallback () {
+    this.items.forEach((item) => {
+      item.addEventListener('change', (e) => {
+        this.items.forEach((item) => {
+          item.checked = item === e.target && e.target.checked
+        })
+      })
+    })
+  }
+
+  get items () {
+    return this.querySelectorAll('input[type="checkbox"]')
+  }
+}