Correct spelling mistakes in readme.md
@@ -22,7 +22,7 @@ This project demonstrates how to use `Nacos + Spring Cloud Alibaba Sidecar` to a
startup.cmd -m standalone
```
-3. Sing in Nacos
+3. Sign in Nacos
Open you browser then input `localhost:8848/nacos` ,you can see the Nacos dashboard ui .
The default username and password are `nacos`
