Merge pull request #240 from stanley-cheung/node_route_guide_minor_fix

doc fix: add db_path param to node route_guide_server command
diff --git a/node/route_guide/README.md b/node/route_guide/README.md
index 85fc416..5460c99 100644
--- a/node/route_guide/README.md
+++ b/node/route_guide/README.md
@@ -354,9 +354,9 @@
 ```
 Run the server, which will listen on port 50051:
 ```shell
-$ node ./route_guide_server.js
+$ node ./route_guide_server.js --db_path=route_guide_db.json
 ```
 Run the client (in a different terminal):
 ```shell
-$ node ./route_guide_client.js
+$ node ./route_guide_client.js --db_path=route_guide_db.json
 ```