Merge pull request #1075 from hcpl/clarify-readme-example

Clarify the README example for local builds

README.md

@@ -20,10 +20,23 @@ You may be looking for:
 
 ## Serde in action
 
+**Cargo.toml**:
+
+```toml
+[dependencies]
+serde = "1.0"
+serde_derive = "1.0"
+serde_json = "1.0"
+```
+
+Click on the "Run" button to have a quick taste:
+
 <a href="http://play.integer32.com/?gist=9003c5b88c1f4989941925d7190c6eec" target="_blank">
 <img align="right" width="50" src="https://raw.githubusercontent.com/serde-rs/serde-rs.github.io/master/img/run.png">
 </a>
 
+**src/lib.rs**:
+
 ```rust
 #[macro_use]
 extern crate serde_derive;