Update fixed-precision docs to reflect constants parsed as DECIMAL

Since 0.198 the default behavior is that decimal literals without an
explicit type specifier (e.g. 1.2) are treated as DECIMAL where
prior to 0.198 they were treated as DOUBLE.

PR: #13281

presto-docs/src/main/sphinx/language/types.rst

@@ -88,8 +88,8 @@ Fixed-Precision
     .. note::
 
         For compatibility reasons decimal literals without explicit type specifier (e.g. ``1.2``)
-        are treated as the values of the ``DOUBLE`` type by default, but this is subject to change
-        in future releases. This behavior is controlled by:
+        are treated as values of the ``DOUBLE`` type by default up to version 0.198. 
+        After 0.198 they are parsed as DECIMAL.
 
           - System wide property: ``parse-decimal-literals-as-double``
           - Session wide property: ``parse_decimal_literals_as_double``