Feature Request External label resolution

[Sherwood Botsford]

One of the things I'm coming up against.  Maintaining a non-small
web site with many internal links is a pain.

Consider:

Suppose that at one point I have

site/
   Images
   Business
   Home
   ...

Later the site gets more complex, and Images has a bunch of sub 
directories.
site/
   Images
     header_rotate
     inventory_pix
     misc
   Business
   Home

When this happens I have to change the link for every pic
on every page.  If I use an image in 6 places, I have to
change it in 6 places.

HOWEVER

Suppose I cleverly used the footnote form of links.

I.e:

[Image alt text][LABEL]

Suppose that markdown was clever enough to reference an external
file (in .markdownrc of course) for the resolution of LABEL.

NOW when I re-arrange the universe, I only have to change the 
reference in this one file, NOT in every file that references it.