added OXID eShop (#679)

closes #677

README.md

@@ -398,6 +398,7 @@ _Recipe management_
 * [OpenCart](https://www.opencart.com) - Free open source shopping cart solution. ([Source Code](https://github.com/opencart/opencart)) `GPLv3` `PHP`
 * [Open Classifieds](http://open-classifieds.com/) - Free open-source, self-hosted CMS for classifieds sites. ([Source Code](https://github.com/open-classifieds/openclassifieds2))  `GPL` `PHP`
 * [Open eShop](https://open-eshop.com/) - Sell your digital goods with licenses and provide support. ([Source Code](https://github.com/open-classifieds/open-eshop))  `GPL` `PHP`
+* [OXID eShop](http://oxidforge.org) - OXID eShop is a flexible open source e-commerce software with a wide range of functionalities ([Demo](http://demoshop.oxid-esales.com/community-edition/), [Source Code](https://github.com/OXID-eSales/oxideshop_ce)) `GPLv3` `PHP`
 * [PrestaShop](https://www.prestashop.com/) - PrestaShop offers a free, open-source and fully scalable e-commerce solution. ([Demo](http://demo.prestashop.com/), [Source Code](https://github.com/PrestaShop/PrestaShop)) `OSLv3` `PHP`
 * [Shoop](https://www.shoop.io/) - Django powered fully customizable open source e-commerce framework for small and large sites. ([B2C demo](https://demo1.shoop.io/), [B2B demo](https://demo2.shoop.io/), [Source Code](https://github.com/shoopio/shoop)) `AGPLv3` `Python`
 * [WooCommerce](https://www.woothemes.com/woocommerce/) - WordPress based e-commerce solution. ([Source Code](https://github.com/woothemes/woocommerce)) `GPL` `PHP`