add requirements.txt

requirements.txt

@@ -0,0 +1,8 @@
+langchain>=1.0.0
+langchain-core>=0.3.0
+langchain-chroma>=0.2.0
+langchain-ollama>=0.2.0
+langchain-text-splitters>=0.3.0
+chromadb>=0.5.0
+tavily-python>=0.3.0
+python-dotenv>=1.0.0