Add a known limitation of Orc reader to docs.

Author: marcinsbd

docs/src/main/sphinx/object-storage/file-formats.md

@@ -31,6 +31,9 @@ with ORC files performed by supported object storage connectors:
 [](file-compression) is automatically performed and some details can be
 configured.
 
+Known limitations:
+Currently, Trino does not support Calendar entry in Orc file metadata. As a results Trino always treats dates and timestamps as values written using Proleptic Gregorian Calendar. This causes incorrect reads of legacy dates and timestamps that were written using Hybrid Calendar.
+
 (parquet-format-configuration)=
 ## Parquet format configuration properties