feat: add modify internal context menu interface #300

docs/en/guide/contextmenu-custom.md

@@ -8,13 +8,25 @@ import Editor from "@hufe921/canvas-editor"
 const instance = new Editor(container, <IElement[]>data, options)
 instance.register.contextMenuList([
     {
+      key?: string;
       isDivider?: boolean;
       icon?: string;
       name?: string; // Use %s for selection text. Example: Search: %s
       shortCut?: string;
+      disable?: boolean;
       when?: (payload: IContextMenuContext) => boolean;
       callback?: (command: Command, context: IContextMenuContext) => any;
       childMenus?: IRegisterContextMenu[];
     }
   ])
 ```
+
+## getContextMenuList
+
+Feature: Get context menu list
+
+Usage:
+
+```javascript
+const contextMenuList = await instance.register.getContextMenuList()
+```