add clone command to instructions

Author: localjo

README.md

@@ -3,7 +3,7 @@ A Google Chrome developer tools extension for use by [Solidus](https://github.co
 **Note:** This is still a work in progress, use at your own risk.
 
 #Build
-* Clone the repo with
+* Clone the repo with `git clone https://github.com/solidusjs/devtools-solidus.git devtools-solidus`
 * Run `npm install` to install dependencies
 * (Optional) Chrome will complain about `.pem` files in some of the dependencies, so you can manually delete `node_modules/socket.io-client/node_modules/engine.io-client/node_modules/ws/test/` to prevent Chrome from warning you when you install the extension.