Fix a link

Author: sarna

doc/Type/IO.pod6

@@ -362,7 +362,7 @@ C<%*ENV<ComSpec> /c> in Windows, C</bin/sh -c> otherwise. All shell meta
 characters are interpreted by the shell, including pipes, redirects,
 environment variable substitutions and so on. Shell escapes are a severe
 security concern and can cause confusion with unusual file names. Use
-L<run|/type/IO#sub_run> if you want to be safe.
+L<run|/type/Proc#sub_run> if you want to be safe.
 
 The return value is of L<type Proc|/type/Proc>.