Document this change as a breaking change

Signed-off-by: Mihai Budiu <mbudiu@feldera.com>

Author: mihaibudiu

site/_docs/history.md

@@ -49,6 +49,12 @@ other software versions as specified in gradle.properties.
 #### Breaking Changes
 {: #breaking-1-42-0}
 
+* [<a href="https://issues.apache.org/jira/browse/CALCITE-7410">CALCITE-7410</a>]
+  Changes the type of the `WINDOW_START` and `WINDOW_END` columns for
+  the table functions `HOP`, `TUMBLE`, `SESSION` to match the original
+  type of the timestamp column.  These types used to be hardwired to
+  `TIMESTAMP(3)`.
+
 * [<a href="https://issues.apache.org/jira/browse/CALCITE-7301">CALCITE-7301</a>]
 Prior to this change, most `SqlNode`s in the `org.apache.calcite.sql.ddl` package could not be unparsed
 when created with `SqlOperator#createCall`. To fix this, those `SqlNode`s now implement their own `SqlOperator`.