FolderShark adds a folder tree to the WordPress Media Library so you can organize attachments by folder — just like a desktop file manager.
The folder sidebar also appears in the media modal wherever you pick media — the post editor, the Customizer, the Site Editor, and widgets — so folders are available everywhere in WordPress.
All files in this plugin are maintained source code and are distributed unminified. The sidebar code lives in sidebar.js inside the plugin folder, and it is included in its original form with no build or minification step, so the full source can be read directly from the package. No build tools are used or required.