fix: source documents list

src/tests/openaiindex_test.py

@@ -42,7 +42,7 @@ def test_02_index_documents(self, mock_print):
         Test indexing documents and assert the type of the index.
         """
         urls = [
-            "https://arxiv.org/pdf/1706.03762.pdf"
+            "https://arxiv.org/pdf/1706.03762.pdf",
             "src/tests/DOCX_TestPage.docx", 
             "src/tests/TEST.md",
             "src/tests/test.html"