added wysiwyg initialization when switching mode

src/container/HtmlDocument.jsx

     if (this.state.content.content_id === -1) return // debug case
 
     this.loadContent()
-    // wysiwyg()
+    wysiwyg()
   }
 
   componentDidUpdate (prevProps, prevState) {
     if (prevState.content.content_id !== this.state.content.content_id) {
       this.loadContent()
     }
+
+    if (prevState.mode === MODE.VIEW && this.state.mode === MODE.EDIT) wysiwyg()
   }
 
   loadContent = async () => {