verarbeitung: added abstracts to json file

verarbeitung/construct_new_graph/export_to_json.py

@@ -31,6 +31,7 @@ def format_nodes(nodes):
         new_dict["author"] = node.contributors
         new_dict["year"] = node.publication_date
         new_dict["journal"] = node.journal
+        new_dict["abstract"] = node.abstract
         if (node.group == 0):
             new_dict["group"] = "Input"
         elif (node.group > 0):