Update doctrine.rst

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

Author: NanoSector

doctrine.rst

@@ -783,7 +783,7 @@ variable. Let's say you want the first or the last comment of a product dependin
     
 .. _doctrine-entity-value-resolver-resolve-target-entities:
 
-Fetch via interfaces
+Fetch via Interfaces
 ~~~~~~~~~~~~~~~~~~~~
 
 Suppose your ``Product`` object implements an interface called ``ProductInterface``.