是否發佈由設定檔控制 [tr-YGRJ]

private cards現在也納入Config as code的設計，用

(define (remove-content-p source-path)
  (define segs (map path->string (explode-path source-path)))
  (and (equal? "content" (first segs))
       (equal? "private" (second segs))))

(define site
  (hash ; ...
        'remove-content-if remove-content-p))

提供這個過濾判斷