Joplin is awesome, but one weakness is publishing note.
Although publishing note is supported in Joplin Cloud plan, but there's one limitation, not supporting TOC in left field.
Markdown document can be used in a wide variety of long document, where Table of contents or outline is very important.
Here I share you the same markdown conversion links in Stackedit, Hackmd, and Joplin
I'd pleased Joplin publishing automatically support TOC in left filed of publishing web page as shown in Stackedit or Stackedit
Stackedit : https://gospel79.netlify.app/
Joplin : 너무나도 중요한 소식 - Joplin Cloud
Another suggestion : Removing Joplin banner image in published web page..
Too large and distracting. It would be better to move the banner to left lower part of web page in small image or text, 'Joplin cloud'