Document Docker deployment for partners

https://redmine.teklia.com/issues/6934

content/deployment/architecture/cloud.mermaid

+graph TD
+
+    lb[Load balancer] --> docker
+
+    subgraph docker[Containers]
+        backend[Arkindex backend]
+        cantaloupe[IIIF server]
+        worker[Arkindex internal worker]
+    end
+
+
+    subgraph services[Managed service]
+
+        minio[S3-compatible storage]
+        redis[Cache]
+        db[Database]
+        solr[Search engine]
+
+    end
+
+    subgraph gpu[GPU-enabled services]
+        ponos -->ml_task[Machine Learning Task]
+    end
+
+    docker --> services
+    gpu --> docker