Change code snippet format

The current code snippet is a single line even there are 2 lines.
Also, want to make is like a code rather than normal text

Author: insukcho

README.md

@@ -33,9 +33,10 @@ To install locally, clone this repository, `cd` into the directory and run:
 1.  Create an account at [Swiftype](https://swiftype.com/) and get your API key from your [Account Settings](https://app.swiftype.com/settings/account).
 
 2.  Configure your client:
-
+    ```
     from swiftype import swiftype
     client = swiftype.Client(api_key='YOUR_API_KEY')
+    ```
 
 3.  Create an `Engine` named e.g. `youtube`: