Table of Contents should be structured according to headers

✨ What new feature or change would you like to see added in RemNote?

the TOC should show the heading structure e.g. in google docs so that the heading sizes can help in navigating the page from there are as well as from the rem itself

🤔 What problem does it solve for you? How would it improve your workflow or experience with RemNote?

🚀 Are there any examples of this suggestion implemented in other apps (if applicable)?

google docs and word doc