Turn accidentally working example for 'unique' into what was probably intended.

(Due to the [...] the original example worked even without the ':as(*.Num)'.)

Author: edwinst

S32-setting-library/Containers.pod

@@ -500,7 +500,7 @@ This makes it possible to effectively compare with other comparison operators,
 too. For example, if you want to compare with C< infix:<==> > semantics, this
 might work for you:
 
-    say +unique [100, 100e0, 200/2], :as(*.Num)   # 1
+    say +unique 100, 100e0, 200/2, :as(*.Num)   # 1
 
 =item squish