support download via aria2 (#797)

docs/en/use_aria2.md

@@ -0,0 +1,40 @@
+# Use `aria2` as downloader
+
+Two environment variables are needed to use `aria2` as the downloader.
+
+```bash
+export COMFYUI_MANAGER_ARIA2_SERVER=http://127.0.0.1:6800
+export COMFYUI_MANAGER_ARIA2_SECRET=__YOU_MUST_CHANGE_IT__
+```
+
+An example `docker-compose.yml`
+
+```yaml
+services:
+
+  aria2:
+    container_name: aria2
+    image: p3terx/aria2-pro
+    environment:
+      - PUID=1000
+      - PGID=1000
+      - UMASK_SET=022
+      - RPC_SECRET=__YOU_MUST_CHANGE_IT__
+      - RPC_PORT=5080
+      - DISK_CACHE=64M
+      - IPV6_MODE=false
+      - UPDATE_TRACKERS=false
+      - CUSTOM_TRACKER_URL=
+    volumes:
+      - ./config:/config
+      - ./downloads:/downloads
+      - ~/ComfyUI/models:/models
+      - ~/ComfyUI/custom_nodes:/custom_nodes
+    ports:
+      - 6800:6800
+    restart: unless-stopped
+    logging:
+      driver: json-file
+      options:
+        max-size: 1m
+```