The idea is to let you create notes that are kept in sync when you scroll
through the document, but that are external to it - the notes themselves live
in an Org-mode file.  As such, this leverages the power of Org-mode (the
notes may have outlines, latex fragments, babel, etc...) while acting like
notes that are made /in/ the document.

Also, I must thank Sebastian for the original idea and inspiration!
Link to the original Interleave package:
https://github.com/rudolfochrist/interleave