add screenshot to readme

Author: localjo

README.md

@@ -1,11 +1,13 @@
 A Google Chrome developer tools extension for use by [Solidus](https://github.com/solidusjs/solidus) developers. Provides real-time introspection of API data and access to Solidus server error logs for use in debugging preprocessors executed in the Node.js runtime environment.
 
+![Solidus DevTools Screenshot](screenshot.png)
+
 #Clone
 * Clone the repo with `git clone https://github.com/solidusjs/devtools-solidus.git devtools-solidus`
 
 #Installation
 * Find the `.crx` file you want in the `dist/` directory. We recommend using the latest version, or you can manually build your own (see below).
-* Open <chrome://extensions> in Chrome
+* Open [chrome://extensions](chrome://extensions) in Chrome.
 * Drag and drop the `.crx` file onto the page and click "Add" to install.
 
 #Manually Build