Commit 9ed85aaf9ae for php.net

commit 9ed85aaf9ae9b6ce94f28665bd8d167319c1f217
Author: Sadetdin EYILI <sad270@users.noreply.github.com>
Date:   Fri Dec 5 20:22:43 2025 +0100

    Add php.github.io/php-src to  CONTRIBUTING.md Technical Resources list (GH-20580)

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index caaca316575..32e8098c08e 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -100,6 +100,7 @@ scattered across different websites, and often outdated. Nonetheless, they can
 provide a good starting point for learning about the fundamentals of the code
 base.

+* https://php.github.io/php-src/
 * https://www.phpinternalsbook.com/
 * https://www.npopov.com/
   * [Internal value representation](https://www.npopov.com/2015/05/05/Internal-value-representation-in-PHP-7-part-1.html), [part 2](https://www.npopov.com/2015/06/19/Internal-value-representation-in-PHP-7-part-2.html)