feat(Node-Exporter): Remove this service

We don't use it, so I prefer remove it on this repository

prometheus/node-exporter/docker-compose.yml

@@ -1,16 +0,0 @@
----
-version: '3.8'
-
-services:
-  node_exporter:
-    image: ${NODE_EXPORTER_IMAGE:-quay.io/prometheus/node-exporter:v1.2.0}
-    container_name: node_exporter
-    command:
-      - '--path.rootfs=/host --collector.textfile.directory=/host/var/lib/node_exporter/textfile_collector'
-    network_mode: host
-    pid: host
-    restart: unless-stopped
-    expose:
-      - 9100
-    volumes:
-      - '/:/host:ro,rslave'