patch 8.2.0867: using \{xxx} for encoding a modifier is not nice

Problem:    Using \{xxx} for encoding a modifier is not nice.
Solution:   Use \<*xxx> instead, since it's the same as \<xxx> but producing a
            different code.

runtime/doc/eval.txt

@@ -1353,8 +1353,8 @@ A string constant accepts these special characters:
 	To use the double quote character it must be escaped: "<M-\">".
 	Don't use <Char-xxxx> to get a utf-8 character, use \uxxxx as
 	mentioned above.
-\{xxx}	like \<xxx> but prepends a modifier instead of including it in the
-	character.  E.g. "\<C-w>" is one character 0x17 while "\{C-w}" is four
+\<*xxx>	Like \<xxx> but prepends a modifier instead of including it in the
+	character.  E.g. "\<C-w>" is one character 0x17 while "\<*C-w>" is four
 	bytes: 3 for the CTRL modifier and then character "W".
 
 Note that "\xff" is stored as the byte 255, which may be invalid in some