add js tag to some code

docs/Script.md

@@ -130,7 +130,7 @@ console.log(s.toString());
 `Script` has an easy interface to parse raw scripts from the newtwork or bitcoind, 
 and to extract useful information.
 An illustrative example (for more options check the API reference)
-```
+```javascript
 var raw_script = new Buffer('5221022df8750480ad5b26950b25c7ba79d3e37d75f640f8e5d9bcd5b150a0f85014da2103e3818b65bcc73a7d64064106a859cc1a5a728c4345ff0b641209fba0d90de6e921021f2f6e1e50cb6a953935c3601284925decd3fd21bc445712576873fb8c6ebc1853ae', 'hex');
 var s = new Script(raw_script);
 console.log(s.toString());