IMPROVEMENT redirect root to docs in langserve app template (#13303)

libs/cli/langchain_cli/project_template/app/server.py

@@ -1,8 +1,15 @@
 from fastapi import FastAPI
+from fastapi.responses import RedirectResponse
 from langserve import add_routes
 
 app = FastAPI()
 
+
+@app.get("/")
+async def redirect_root_to_docs():
+    return RedirectResponse("/docs")
+
+
 # Edit this to add the chain you want to add
 add_routes(app, NotImplemented)