corrected json formatting in readme and added new entry to TOC

Author: John Doherty

README.MD

@@ -9,6 +9,7 @@ JavaScript browser automation framework using official [selenium-webdriver](http
 * [Installation](#installation)
 * [Usage](#usage)
   * [Options](#options)
+  * [Default configuration file](#default-configuration-file)
   * [Feature files](#feature-files)
   * [Step definitions](#step-definitions)
   * [Page objects](#page-objects)
@@ -62,36 +63,38 @@ By default tests are run using Google Chrome, to run tests using another browser
 | Phantom JS | `-b phantomjs`
 
 ### Default configuration file
+
 Many configuration options can be defaulted so they don't need to be overridden on the command line.
 The JSON keys are the "long name" from the command line options.
-  
+
 A "selenium-cucumber-js.json" file at the root of your project allows you to specify a subset of configuration overrides.
 
-For example the following duplicates default configuration.  
+For example the following duplicates default configuration:
 
 ```json
 {
-    steps: './step-definitions',
-    pageObjects: './page-objects',
-    sharedObjects: './shared-objects',
-    reports: './reports',
-    browser: 'chrome',
-    timeout: 10000
+    "steps": "./step-definitions",
+    "pageObjects": "./page-objects",
+    "sharedObjects": "./shared-objects",
+    "reports": "./reports",
+    "browser": "chrome",
+    "timeout": 10000
 }
 ```
+
 This would set configuration to match the expected directory structure of IntelliJ's Cucumber plugin, and make default timeout one minute.
 Note that the default browser has not been overridden and will remain 'chrome'.
+
 ```json
 {
-    steps: './features/step_definitions',
-    pageObjects: './features/page_objects',
-    sharedObjects: './features/shared_objects',
-    reports: './features/reports',
-    timeout: 60000
+    "steps": "./features/step_definitions",
+    "pageObjects": "./features/page_objects",
+    "sharedObjects": "./features/shared_objects",
+    "reports": "./features/reports",
+    "timeout": 60000
 }
 ```
 
-
 ### Feature files
 
 A feature file is a [Business Readable, Domain Specific Language](http://martinfowler.com/bliki/BusinessReadableDSL.html) file that lets you describe software’s behavior without detailing how that behavior is implemented. Feature files are written using the [Gherkin syntax](https://github.com/cucumber/cucumber/wiki/Gherkin) and must live in a folder named **features** within the root of your project.