FEATURE REQUEST: Function to show nested files in TOC

[Patrik-Tkacik]

I was unable to find a way to make nested notes/files.md be visible in the table of contents, here is an example:

Files structure
Notes - parent folder
Notes/index.md - this file contains TOC
Notes/topics.md
Notes/to-learn.md
Notes/english.md

that is what the plugin can do now, but it can't files like these in the Notes/index.md
Notes/Mathematics/index.md
Notes/Mathematics/linear-algebra.md

[Patrik-Tkacik]

Didn't want to wait so I made the changes: #101 - pull request. Thank you for the plugin.