fix test file

beautiful-racket-demo/jsonic-demo/jsonic-test.rkt

@@ -1,13 +1,11 @@
 #lang jsonic-demo
 // a line comment
 [
-    @$ 'null $@,
-    @$ #f $@,
-    @$ #t $@,
-    @$ (* 6 7) $@,
-    @$ "string" $@,
-    @$ (list "array" "of" "strings") $@,
-    @$ (hash 'key-1 42
-             'key-2 "value"
-             'key-3 (hash 'subkey 21)) $@
+  @$ 'null $@,
+  @$ (* 6 7) $@,
+  @$ (= 2 (+ 1 1)) $@,
+  @$ (list "array" "of" "strings") $@,
+  @$ (hash 'key-1 'null
+           'key-2 (even? 3)
+           'key-3 (hash 'subkey 21)) $@
 ]