improve type definition of write-plist

Author: joergen7

typed-racket-more/typed/xml/plist.rkt

@@ -23,4 +23,4 @@
   [plist-value? (-> Any Boolean)]
   [plist-dict? (-> Any Boolean)]
   [read-plist (-> Input-Port Plist-Value)]
-  [write-plist (-> Plist-Dict Output-Port Void)])
+  [write-plist (-> Plist-Value Output-Port Void)])