Rackety and minor edits.

collects/scribblings/gui/widget-gallery.rkt

@@ -1,12 +1,10 @@
-(module widget scheme/base
+#lang racket/base
 (require racket/string
          "common.rkt")
 
 (provide showcase-widget)
 
-  (define-syntax showcase-widget
-    (syntax-rules ()
-      ((_ widget code ...)
+(define-syntax-rule (showcase-widget widget code ...)
   (begin
     (racketlink widget
                 (image #:suffixes
@@ -15,4 +13,4 @@
                                       (string-trim (symbol->string 'widget)
                                                    "%"
                                                    #:left? #f))))
-         (racketblock code ...))))))
+    (racketblock code ...)))

collects/scribblings/gui/widget-gallery.scrbl

@@ -4,7 +4,12 @@
 
 @title[#:style '(toc quiet)]{Widget Gallery}
 
-This section gives an overview of the main widgets available in the Racket Graphical Interface Toolkit and each image points to its full documentation.
+@; Note: Instructions for taking widget screenshots are avaiable at:
+@;   ./taking-screenshots/instructions
+
+This section shows the main widgets available in the Racket Graphical User
+Interface Toolkit. Each image is a link to the documentation of the relevant
+widget.
 
 @(showcase-widget button%
 (define button (new button%