Fix dot call in AST docs (#33247)

Author: tkf

doc/src/devdocs/ast.md

@@ -59,7 +59,7 @@ call. Finally, chains of comparisons have their own special expression structure
 | `a==b`      | `(call == a b)`           |
 | `1<i<=n`    | `(comparison 1 < i <= n)` |
 | `a.b`       | `(. a (quote b))`         |
-| `a.(b)`     | `(. a b)`                 |
+| `a.(b)`     | `(. a (tuple b))`         |
 
 ### Bracketed forms