Perhaps add a mechanism for defining custom directory structure/hierarchy  #24

instead of adding a 'this' or 'that' folder, perhaps a mechanism for defining the folder structure.
eg maybe 'People' is not important because you're talking about zoology so you instead have an 'Animals' directory

/my folder
/another folder
/some other folder
/structure.substrate <- ----- this file contains some data structure that tells about the hierarchy/directory structure

related:
#17
#16
#18