pict: disk: Add docstring.

* pict.scm (disk): Add docstring.

1 files changed, 2 insertions, 0 deletions

diff --git a/pict.scm b/pict.scm
index 2eb7db6..16e067e 100644
--- a/pict.scm
+++ b/pict.scm
@@ -689,6 +689,8 @@ override the line color and line thickness."
 (define* (disk size
                #:key
                (color "black"))
+  "Return a disk with an outer diameter of SIZE.  It is filled with
+the given COLOR."
   (fill (circle size #:border-width 0 #:border-color "none") color))
 
 (define* (ellipse w h