Update doctrine/associations.rst

Co-authored-by: Oskar Stark <[email protected]>

Author: fishbone1

doctrine/associations.rst

@@ -585,7 +585,7 @@ on that ``Product`` will be set to ``null`` in the database.
 
     Please be aware that the inverse side could be associated with a large amount of records.
     I.e. there could be a large amount of products with the same category.
-    In this case `$this->products->contains($product)` could lead to unwanted database
+    In this case ``$this->products->contains($product)`` could lead to unwanted database
     requests and very high memory consumption with the risk of hard to debug "Out of memory" errors.
 
     So make sure if you need an inverse side and check if the generated code could lead to such issues.