add "Program With Gio | PHP 8 course by Gio"

Adding "Program With Gio | PHP 8 course by Gio" to the PHP Videos list.

README.md

 * [Laravel YouTube Channel](https://www.youtube.com/channel/UCfO2GiQwb-cwJTb1CuRSkwg) - The official Laravel YouTube channel.
 * [Programming with Anthony](https://www.youtube.com/playlist?list=PLM-218uGSX3DQ3KsB5NJnuOqPqc5CW2kW) - A video series by Anthony Ferrara.
 * [SymfonyCasts](https://symfonycasts.com/) - Screencasts and tutorials about PHP and Symfony.
+* [Program With Gio](https://www.youtube.com/playlist?list=PLr3d3QYzkw2xabQRUpcZ_IBk9W50M9pe-) - PHP 8 course by Gio.
 
 ### PHP Conferences
 *PHP conferences.*