chore: update readme

Author: SSebo

README.md

@@ -14,16 +14,18 @@ Reading the short [Basic Terms](https://github.com/FeatureProbe/FeatureProbe/blo
 
 ## Try Out Demo Code
 
-We provide a runnable demo code for you to understand how FeatureProbe SDK is used.
+We provide a runnable [demo](https://github.com/FeatureProbe/server-sdk-rust/tree/main/examples) for you to understand how FeatureProbe SDK is used.
 
-1. Start FeatureProbe Service with docker composer. [How to](https://github.com/FeatureProbe/FeatureProbe#1-starting-featureprobe-service-with-docker-compose)
+1. Use featureprobe.io online service. [Go to](https://featureprobe.io/login)
+   
+   Or setup FeatureProbe service with docker composer. [How to](https://github.com/FeatureProbe/FeatureProbe#1-starting-featureprobe-service-with-docker-compose)
 2. Download this repo and run the demo program:
  ```bash
  git clone https://github.com/FeatureProbe/server-sdk-rust.git
  cd server-sdk-rust
  cargo run --example demo
  ```
-3. Find the Demo code in [examples](https://github.com/FeatureProbe/server-sdk-rust/tree/main/examples), 
+3. Find the Demo code [here](https://github.com/FeatureProbe/server-sdk-rust/tree/main/examples), 
  do some change and run the program again.
  ```bash
  cargo run --example demo