Updated README

README.md

@@ -27,7 +27,7 @@ technologies used on websites.  It detects
 
 ## apps.json
 
-### Example
+#### Example
 
 ```javascript
 "Application Name": { 
@@ -45,7 +45,7 @@ technologies used on websites.  It detects
 
 ### JSON fields
 
-field      | type   | required | description
+field      | type   | description
 -----------|--------|-----------------------
 cats       | array  | List of category IDs. See [apps.json](https://github.com/ElbertF/Wappalyzer/blob/master/share/apps.json) for the complete list.
 confidence | object | Indicates less reliable patterns that may cause false positives. The aim is to achieve a combined confidence of 100%. Defaults to 100% for unspecified fields.
@@ -57,6 +57,8 @@ url        | string | URL of the page, e.g. `http://wordpress.com/index.php`.
 meta       | object | HTML meta tags, e.g. `generator`.
 script     | string | `src` attribute of HTML script tags, e.g. `jquery.js`.
 
+Except `cats`, all fields are optional.
+
 
 ## Drivers