Improve dependency documentation

README.md

 
     http://localhost:8080/src/records/posts/1
 
-The non-compiled code resides in the "`src`" and "`vendor`" directories.
+The non-compiled code resides in the "`src`" and "`vendor`" directories. The "`vendor`" directory contains the dependencies.
 
 ### Updating dependencies
 
 
     php update.php
 
-This script will install and run [Composer](https://getcomposer.org/) to update the required dependencies in the "`vendor`" directory.
+This script will install and run [Composer](https://getcomposer.org/) to update the dependencies.
 
 NB: The update script will also patch the dependencies in the vendor directory for PHP 7.0 compatibility.