adds docsting on table format to decorators

dlt/extract/decorators.py

@@ -317,6 +317,8 @@ def resource(
         merge_key (str | Sequence[str]): A column name or a list of column names that define a merge key. Typically used with "merge" write disposition to remove overlapping data ranges ie. to keep a single record for a given day.
         This argument also accepts a callable that is used to dynamically create tables for stream-like resources yielding many datatypes.
 
+        table_format (Literal["iceberg"], optional): Defines the storage format of the table. Currently only "iceberg" is supported on Athena, other destinations ignore this hint.
+
         selected (bool, optional): When `True` `dlt pipeline` will extract and load this resource, if `False`, the resource will be ignored.
 
         spec (Type[BaseConfiguration], optional): A specification of configuration and secret values required by the source.