chore: update README on custom node example

Author: harbournick

examples/vue-custom-node-example/README.md

@@ -1,13 +1,11 @@
 # SuperDoc
-## SuperDoc: Creating a custom mark
+## SuperDoc: Creating a custom node
 
-An example of creating a custom Mark to use with SuperDoc.
+An example of creating a custom node to use with SuperDoc.
 Note: Requires `SuperDoc 0.10.15` or later
 
-[We create a custom mark here](https://github.com/Harbour-Enterprises/SuperDoc/blob/main/examples/vue-custom-mark/src/custom-mark.js)
-Note that we added a custom command to the mark, called setMyCustomMark. We can now insert this mark by calling this command from `superdoc.activeEditor.commands`
+[We create a custom node here](https://github.com/Harbour-Enterprises/SuperDoc/blob/develop/examples/vue-custom-node-example/src/custom-node.js#L62)
+Note that we added a custom command to the node, called insertCustomNode. We can now insert this node by simply calling this command from editor.commands.insertCustomNode
 
 [Then we can pass it into the editor via the `editorExtensions` key](https://github.com/Harbour-Enterprises/SuperDoc/blob/e724d31eaba50a423ed0d73a4264a09b33d06eaa/examples/vue-custom-mark/src/App.vue#L20)
 
-## Exporting the docx
-This example also shows one way to export the docx to a blob whenever the content changes in the editor