Worked on improving the accuracy of documentation for the symfony/symfony-docs repository, focusing on clarifying the API behavior of the BeforeSendMailEvent. Addressed a documentation bug by updating the event_dispatcher.rst file to correctly state that the setSubject method does not return a value, ensuring that the example code accurately reflects the actual API. This change helps reduce confusion for developers, streamlines onboarding, and decreases support requests. The work involved careful review and editing of reStructuredText (rst) documentation, demonstrating attention to detail and a commitment to maintaining high-quality technical documentation for the Symfony PHP framework community.