Add English Advanced WordPress Theme Development Course (#10016)

* Add Advanced WordPress Theme Development Course

* try to fix error

* update index

* add more resources on wordpress category

courses/free-courses-en.md

@@ -108,6 +108,7 @@
 * [Web Development](#web-development)
 * [Web3](#web3)
 * [Windows Phone](#windows-phone)
+* [WordPress](#wordpress)
 * [YAML](#yaml)
 
 
@@ -1577,6 +1578,15 @@
 * [Windows Phone 8.1 Development for Absolute Beginners](https://web.archive.org/web/20150213035325/http://channel9.msdn.com/Series/Windows-Phone-8-1-Development-for-Absolute-Beginners) - Bob Tabor, Matthias Shapiro, Larry Lieberman *(:card_file_box: archived)*
 
 
+### WordPress
+
+* [Advanced Custom Fields (ACF) Tutorials](https://www.youtube.com/playlist?list=PLTbrc9HXDstqm7yNAadSwwypHR_iEWLR_) - WPTuts
+* [Advanced WordPress Theme Development Course](https://www.youtube.com/playlist?list=PLD8nQCAhR3tT3ehpyOpoYeUj3KHDEVK9h) - Imran Sayed - Codeytek Academy
+* [Astra Theme Tutorials](https://www.youtube.com/playlist?list=PLgJeRQxEOJmoYLvxOCq3DJB5q6LWJWKjH) - Ferdy Korpershoek
+* [Elementor Pro Tutorials](https://www.youtube.com/playlist?list=PLgJeRQxEOJmq5hR8yETsu3zPFmpoxCeMq) - Ferdy Korpershoek
+* [How To Customize WooCommerce](https://www.youtube.com/playlist?list=PLTbrc9HXDstpihLrQIWtmExd9f1tiAYET) - WPTuts
+
+
 ### YAML
 
 * [Complete YAML Course - Beginner to Advanced for DevOps and more!](https://www.youtube.com/watch?v=IA90BTozdow) - Kunal Kushwaha