Add docs to filters

Author: mnoszczak

labelbox/schema/export_filters.py

@@ -11,4 +11,18 @@
 
 class ProjectExportFilters(TypedDict):
     label_created_at: Optional[Tuple[str, str]]
+    """ Date range for labels created at
+    Formatted "YYYY-MM-DD" or "YYYY-MM-DD hh:mm:ss"
+    Examples: 
+    >>>   ["2000-01-01 00:00:00", "2050-01-01 00:00:00"]
+    >>>   [None, "2050-01-01 00:00:00"]
+    >>>   ["2000-01-01 00:00:00", None]
+    """
     last_activity_at: Optional[Tuple[str, str]]
+    """ Date range for last activity at
+    Formatted "YYYY-MM-DD" or "YYYY-MM-DD hh:mm:ss"
+    Examples: 
+    >>>   ["2000-01-01 00:00:00", "2050-01-01 00:00:00"]
+    >>>   [None, "2050-01-01 00:00:00"]
+    >>>   ["2000-01-01 00:00:00", None]
+    """