I’d rather provide configuration examples than real config files. In my project there is setup.default.php file in root directory that every user need to copy as setup.php and amend to match local environment. Additionally, to prevent checking in back customised setup files there is a rule for it in .svnignore.
$ echo 'setup.php' > .svnignore
$ svn propset svn:ignore -F .svnignore .