[O] map function definitions to org src blocks?

[Matt Price]

I feel like I saw someone do this but can't find it in my notes. When
tangling code to elisp, is it possible to point ~describe-function~ to the
original org-mode source (or at least the src block) as the "source code"
for the function, rather than the resultant .e file produced by
org-babel-tangle? Seems like this would make a whole lot of things
significantly easier when writing emacs inits, for instnace.