Remove StorageManager::Hybrid and StorageManager::Match. These were used to store uploads on different servers based on the post ID or file sample type. This is no longer used in production because in hindsight it's a lot more difficult to manage uploads when they're fragmented across different servers. If you need this, you can do tricks with network filesystems to get the same effect. For example, if you want to store some files on server A and others on server B, then mount servers A and B as network filesystems (with e.g. sshfs, Samba, NFS, etc), and use symlinks to point subdirectories at either server A or B.
Config
This directory contains configuration files for Danbooru.
To configure your Danbooru instance, copy danbooru_default_config.rb to danbooru_local_config.rb and edit it. See danbooru_default_config.rb for details.
The only file here that end users need to be concerned about is danbooru_default_config.rb. The rest of the files here are internal Rails-related configuration files that end users shouldn't need to edit.