This PR was squashed before being merged into the 3.3 branch (closes#8260).Discussion----------Delete use_virtuals_forms.rstAs this is about an option from Symfony 2 and removed years ago in Symfony 2.3, this can be removed from the docs for Symfony 3Commits-------4c66f31 Delete use_virtuals_forms.rst

* 3.3: (40 commits)  [#8273] fix bundle registration code  [#8273] minor rewording  Reworded the built-in web server articles for Symfony 3.3  fix diff code block highlighting  [#8231] fix reStructuredText syntax  Specified import order of config files  [#7981] revert some changes  Update upload_file.rst  Update usage.rst  Update doctrine.rst  Update usage.rst  [#8260] add missing redirection map entry  Delete use_virtuals_forms.rst  Added a missing redirection  Update validation_group_service_resolver.rst  Update redirection_map  Update button_based_validation.rst  Delete group_service_resolver.rst  Create validation_group_service_resolver.rst  [#8290] fix minor typo  ...

* 3.4: (42 commits)  [#8273] fix bundle registration code  [#8273] minor rewording  Reworded the built-in web server articles for Symfony 3.3  fix diff code block highlighting  [#8269] minor rewording  [Console] Commands auto-registration is deprecated  [#8231] fix reStructuredText syntax  Specified import order of config files  [#7981] revert some changes  Update upload_file.rst  Update usage.rst  Update doctrine.rst  Update usage.rst  [#8260] add missing redirection map entry  Delete use_virtuals_forms.rst  Added a missing redirection  Update validation_group_service_resolver.rst  Update redirection_map  Update button_based_validation.rst  Delete group_service_resolver.rst  ...