fix: Address empty field schema in for SDK-based type conforming

See #239 (comment)

tap_postgres/client.py

@@ -2,6 +2,7 @@
 
 This includes PostgresStream and PostgresConnector.
 """
+
 from __future__ import annotations
 
 import datetime
@@ -123,7 +124,17 @@ def to_jsonschema_type(
             type_name = type(sql_type).__name__
 
         if type_name is not None and type_name in ("JSONB", "JSON"):
-            return {}
+            return {
+                "examples": [
+                    "A JSON string",
+                    1.23,
+                    123,
+                    {"key": "value"},
+                    ["list", "of", "values"],
+                    True,
+                    None,
+                ],
+            }
 
         if (
             type_name is not None