[SCB-29] add README document for config-apollo

samples/config-apollo-sample/README.md

@@ -0,0 +1,42 @@
+## Use Apollo as Configuration Center
+
+To use Apollo as configuration source in ServiceComb Java Chassis services:
+
+* Start Apollo service and create a project to associate with Chassis service, then generate a token
+
+  [How to use Apollo configuration center](http://servicecomb.incubator.apache.org/cn/users/dynamic-config/)
+
+
+* Import `config-apollo` in pom:
+
+  ```xml
+  <dependency>
+        <groupId>org.apache.servicecomb</groupId>
+        <artifactId>config-apollo</artifactId>
+   </dependency>
+  ```
+
+* Configurations for Apollo itself in `microservice.yaml`, for example:
+
+  ```yaml
+  apollo:
+    config:
+      serverUri: http://127.0.0.1:8070	#Apollo portal server address
+      serviceName: apollo-test		#service name
+      env: DEV				#default valueDEV
+      clusters: test-cluster		#default value default
+      namespace: application		#default value application
+      token: 				#get token from Apollo web pages
+  ```
+
+* Start Chassis service and update configurations in Apollo portal service.
+
+  [Need to start service center first](http://servicecomb.incubator.apache.org/users/setup-environment/#)
+
+
+## More
+
+[Apollo Doc](https://github.com/ctripcorp/apollo/wiki)
+
+[Use Apollo In ServiceComb](http://servicecomb.incubator.apache.org/cn/users/dynamic-config/)
+