Feature Request: Add option to open markdown in editor or preview from the TOC

[Alex-Lewandowski]

In recent versions of Jupyter, you can no longer right-click on an open markdown file and choose to open it in editor or preview mode. Users can adjust the default Jupyter behavior when opening Markdown to either preview or editor, so we cannot assume how a markdown file will be opened from the TOC.

Currently, if the TOC opens the markdown in the wrong mode, you need to leave the TOC, open the file terminal, navigate to the markdown file, right-click it, and select how to open it. Users should be able to do this by right-clicking the entry in the TOC directly.