the Jenkins “Config File Provider” plugin — allows you to copy various similar configuration files to all your nodes — also adds the ability to edit those files through the Jenkins UI

• https://wiki.jenkins-ci.org/display/JENKINS/Config+File+Provider+Plugin

Adds the ability to provide configuration files (i.e., settings.xml for maven, XML, groovy, custom files, etc.) loaded through the Jenkins UI which will be copied to the job’s workspace.