Replace broken resource URL (#8365)

* Replace broken resource URL with a better FreeCodeCamp article

Replace broken resource URL with a better FreeCodeCamp article  

The previous resource URL was not found, so I replaced it with a more relevant article from FreeCodeCamp:  
https://www.freecodecamp.org/news/what-is-an-orm-the-meaning-of-object-relational-mapping-database-tools

* Update src/data/roadmaps/php/content/object-relational-mapping-orm@SeqGIfcLuveZ2z5ZSXcOd.md

---------

Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

src/data/roadmaps/php/content/object-relational-mapping-orm@SeqGIfcLuveZ2z5ZSXcOd.md

@@ -11,4 +11,4 @@ $entityManager->flush();
 
 Visit the following resources to learn more:
 
-- [@article@Object Relational Mapping (ORM)](https://www.doctrine-project.org/projects/doctrine-orm/en/2.7/tutorials/getting-started.html)
+- [@article@What is an Object Relational Mapping (ORM)](https://stackoverflow.com/questions/1279613/what-is-an-orm-how-does-it-work-and-how-should-i-use-one#answer-1279678)