Update README.md

Author: Qin

README.md

@@ -1,2 +1,9 @@
-# dotnet-nodejs-docker
-Docker images for .Net Core SDK + NodeJS
+## This images for the .NET Core SDK and Node.js environment.
+
+### For example:
+.net core sdk **2.2** + node.js **10.x**
+
+    docker pull dotnetimages/microsoft-dotnet-core-sdk-nodejs:2.2_10.x
+others environment please visit the the repository tags page:
+
+[https://hub.docker.com/r/dotnetimages/microsoft-dotnet-core-sdk-nodejs/tags](https://hub.docker.com/r/dotnetimages/microsoft-dotnet-core-sdk-nodejs/tags)