Update README.md

Author: kaisong1990

README.md

@@ -21,7 +21,7 @@ This project has adopted the [Microsoft Open Source Code of Conduct](https://ope
 For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or
 contact [[email protected]](mailto:[email protected]) with any additional questions or comments.
 
-## Security Library
+## Security Library 
 
 This library controls how users sign-in and access services. We recommend you always take the latest version of our library in your app when possible. We use [semantic versioning](http://semver.org) so you can control the risk associated with updating your app. As an example, always downloading the latest minor version number (e.g. x.*y*.x) ensures you get the latest security and feature enhanements but our API surface remains the same. You can always see the latest version and release notes under the Releases tab of GitHub.