Shopkeeper4 integration

Snippet to display categories, products, filters, bread crumbs, etc. from the MongoDB database. For this extra to work, Shopkeeper 4 (https://github.com/andchir/shopkeeper4) must be installed on your or remote server. For the shopping cart you need to use the snippet [ShoppingCart](https://modx.com/extras/package/shoppingcart).

Documentation: https://github.com/andchir/modx-shopkeeper4/wiki

beta version