patch 9.0.2162: Vim9: type documentation out-dated

Problem:  Vim9: type documentation out-dated
Solution: Update documentation, fix typo in type alias
          definition

closes: #13684

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/vim.h b/src/vim.h
index 2d5ae99..3aa04f5 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -2181,7 +2181,7 @@
 #define VAR_TYPE_INSTR	    11
 #define VAR_TYPE_CLASS	    12
 #define VAR_TYPE_OBJECT	    13
-#define VAR_TYPE_TYPEALIAS  15
+#define VAR_TYPE_TYPEALIAS  14
 
 #define DICT_MAXNEST 100	// maximum nesting of lists and dicts