Add backmarket.com to adopters list
* [Hualala](https://www.hualala.com) uses CoreDNS in Kubernetes using default configuration, in its Lab. Expected to be in production soon.
* [Hellofresh](https://www.hellofresh.com/) uses CoreDNS in multiple Kubernetes clusters, with Forward plugin.
* [Render](https://render.com) uses CoreDNS in production across all its Kubernetes clusters.
+* [BackMarket](https://www.backmarket.com) uses CoreDNS within Kubernetes in production, with standard configuration.
