fix code example, in async.md (#1388)

diff --git a/docs/async.md b/docs/async.md
index 1cd51b00f14383225b8ba227e00383d38374080b..3238097a8291221420f8525b1b51d7efe4d61ae5 100644 (file)
--- a/docs/async.md
+++ b/docs/async.md
@@ -169,7 +169,7 @@ from starlette.responses import HTMLResponse
 from starlette.routing import Route
 
 
-async def hello():
+async def hello(request):
     return HTMLResponse("Hello World!")