Feat/serialize deserialize (#508)

Co-authored-by: Taranjeet Singh <reachtotj@gmail.com>

embedchain/loaders/local_qna_pair.py

@@ -1,6 +1,8 @@
+from embedchain.helper_classes.json_serializable import register_deserializable
 from embedchain.loaders.base_loader import BaseLoader
 
 
+@register_deserializable
 class LocalQnaPairLoader(BaseLoader):
     def load_data(self, content):
         """Load data from a local QnA pair."""