The skeleton command created a mirror of the directory structure of a game server. This allows you to create a skeleton directory of custom files, configs, maps etc.
Standard: ./gameserver skeleton
Short: ./gameserver sk
The skeleton directory is created in skel.
Skeleton can be used alongside version control software like git or backed up to save custom configurations for a game server. If a change is added to your git repository/backup it is possible to pull/copy the updates to your game server. If you want to re-deploy a game server you can create a fresh installation and pull/copy in the custom changes over the top of the fresh install.