added comment for custom event

src/container/HtmlDocument.jsx

 
   handleClickBtnCloseApp = () => {
     this.setState({ isVisible: false })
-    GLOBAL_dispatchEvent({type: 'appClosed', data: {}})
+    GLOBAL_dispatchEvent({type: 'appClosed', data: {}}) // handled by tracim_front::src/container/WorkspaceContent.jsx
   }
 
   handleSaveEditTitle = async newTitle => {

src/container/PopupCreateHtmlDocument.jsx

   handleChangeNewContentName = e => this.setState({newContentName: e.target.value})
 
   handleClose = () => GLOBAL_dispatchEvent({
-    type: 'hide_popupCreateContent',
+    type: 'hide_popupCreateContent', // handled by tracim_front:dist/index.html
     data: {
       name: this.state.appName
     }
       this.handleClose()
 
       GLOBAL_dispatchEvent({
-        type: 'openContentUrl',
+        type: 'openContentUrl', // handled by tracim_front:src/container/WorkspaceContent.jsx
         data: {
           idWorkspace: jsonSaveNewHtmlDoc.workspace_id,
           contentType: this.state.appName,