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/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 5d61035..2a4bd4c 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -2558,6 +2558,8 @@
 v:t_class	Value of |class| type.  Read-only.  See: |type()|
 					*v:t_object* *t_object-variable*
 v:t_object	Value of |object| type.  Read-only.  See: |type()|
+					*v:t_typealias* *t_typealias-variable*
+v:t_typealias	Value of |typealias| type.  Read-only.  See: |type()|
 
 				*v:termresponse* *termresponse-variable*
 v:termresponse	The escape sequence returned by the terminal for the |t_RV|