Update Readme

Author: WooSignal

README.md

@@ -17,7 +17,7 @@
 * Get Customers Info (Billing and Shipping)
 * Update Customers details
 
-To use this API you must have the [WP Json API Plugin](https://woosignal.com/plugins/wordpress/wp-json-api) installed first on your WordPress site, you can download it via the WooSignal website.
+To use this API you must have the [WP JSON API Plugin](https://woosignal.com/plugins/wordpress/wp-json-api) installed first on your WordPress site, you can download it via the WooSignal website.
 
 ### Getting Started #
 In your flutter project add the dependency: