Fixed a syntax issue

Author: javiereguiluz

doctrine/events.rst

@@ -7,8 +7,8 @@ Doctrine Events
 `Doctrine`_, the set of PHP libraries used by Symfony to work with databases,
 provides a lightweight event system to update entities during the application
 execution. These events, called `lifecycle events`_, allow to perform tasks such
-as _"update the createdAt property automatically just before persisting entities
-of this type"_.
+as *"update the createdAt property automatically just before persisting entities
+of this type"*.
 
 Doctrine triggers events before/after performing the most common entity
 operations (e.g. ``prePersist/postPersist``, ``preUpdate/postUpdate``) and also