Making sure quill editor updates with has_many

What:

* adding an event listerner so when people add a 'has_many' relationship
the quill editor is initialized correctly on any fields;

Why:

* If you have a nested has_many attributes in active admin, the form
is not created until you click the 'Add New ObjectName' button. This
triggers a jQuery event called 'has_many_add:after' which you can use to
trigger the re init of the quill editor.
* 9a33a081c9/app/assets/javascripts/active_admin/lib/has_many.es6 (L52)

app/assets/javascripts/activeadmin/quill_editor_input.js

@@ -1,4 +1,12 @@
-window.onload = function() {
+window.onload = function () {
+  initQuillEditors();
+}
+
+$(document).on('has_many_add:after', function() {
+  initQuillEditors();
+});
+
+var initQuillEditors = function() {
   var editors = document.querySelectorAll( '.quill-editor' );
   var default_options = {
     modules: {
@@ -19,9 +27,11 @@ window.onload = function() {
 
   for( var i = 0; i < editors.length; i++ ) {
     var content = editors[i].querySelector( '.quill-editor-content' );
-    if( content ) {
+    var isActive = editors[i].classList.contains('quill-editor--active');
+    if( content && !isActive) {
       var options = editors[i].getAttribute( 'data-options' ) ? JSON.parse( editors[i].getAttribute( 'data-options' ) ) : default_options;
       editors[i]['_quill-editor'] = new Quill( content, options );
+      editors[i].classList += ' quill-editor--active';
     }
   }