Add some comments

core.rkt

@@ -82,12 +82,14 @@
 (define-syntax-rule [define-oracle name . table]
   (define name (oracle (quote table))))
 
+;; create an asset
 (define (asset name table)
   (define (mk-feature feature)
     (list (car feature) (smart-string-append (cdr feature))))
   (let [(stuff (map mk-feature table))]
     `(asset ,name ,stuff)))
 
+;; concatenate strings, adding whitespace if necessary
 (define (smart-string-append list)
   (define (ensure-leading-space str)
     (if (char-whitespace? (string-ref str 0))