Added/modified documentation for function arguments.

diff --git a/windows/cursoricon.c b/windows/cursoricon.c
index f3d4d7f..e52adea 100644
--- a/windows/cursoricon.c
+++ b/windows/cursoricon.c
@@ -1379,7 +1379,7 @@
  *	A handle to the previous cursor shape.
  */
 HCURSOR WINAPI SetCursor(
-	         HCURSOR hCursor /* Handle of cursor to show */
+	         HCURSOR hCursor /* [in] Handle of cursor to show */
 ) {
     HCURSOR hOldCursor;