add portainer; move nginx-p-m to the correct group

apps/docker/portainer.md

@@ -0,0 +1,24 @@
+# Portainer
+A nice UI for managing docker/kubernetes/swarm containers.
+
+<br>
+
+- [Homepage](https://www.portainer.io)
+- [Github repo](https://github.com/portainer/portainer)
+
+
+## docker-compose.yml
+```yml
+---
+services:
+  portainer:
+    image: portainer/portainer-ce
+    container_name: portainer
+    restart: unless-stopped
+    ports:
+      - 8000:8000
+      - 9443:9443
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
+      - ./data:/data
+```