update loader module

app.py

@@ -174,7 +174,7 @@ def main():
                     print('file - type : ', file.type)
                     if file.type == 'text/plain':
                         #file is .txt
-                        raw_text += get_text_file(file)
+                        doc_list.extend(get_text_file(file))
                     elif file.type in ['application/octet-stream', 'application/pdf']:
                         #file is .pdf
                         doc_list.extend(get_pdf_text(file))
@@ -183,7 +183,7 @@ def main():
                         raw_text += get_csv_file(file)
                     elif file.type == 'application/json':
                         # file is .json
-                        raw_text += get_json_file(file)
+                        doc_list.extend(get_json_file(file))
                     elif file.type == 'application/x-hwp':
                         # file is .hwp
                         raw_text += get_hwp_file(file)