The Shop Site skeleton is a Grav skeleton and includes a user folder giving an example of a store set up using Grav.
To install this package, you will essentially be replacing the default user folder with the skeleton. To do this, download the zip version of this repository and unzip it under /your/site/grav/. Then, rename the folder to user.
If a user folder already exists, back up the folder to a safe place, delete it (if there is no custom content in it you wish to keep) or replace its contents with the files in the unzipped folder.
You should now have all the skeleton files under
/your/site/grav/user/
NOTE: This skeleton is a modular component for Grav which requires Grav, the Error and Problems plugins, and a theme to be installed in order to operate. If you download this skeleton as part of a pre-assembled package from GetGrav.org, you should have everything you need to get started.