update docker-compose info in README

README.md

@@ -3,6 +3,27 @@ Run a seafile client inside docker witch can sync files from seafile repositorie
 
 See docker-compose how to use.
 
+## Docker-compose example:
+```yaml
+version: '3'
+services:
+  seafile-client:
+    restart: always
+    build: .
+    container_name: seafile-client
+    environment:
+      - LIBRARY_ID=<your-library-id-here>
+      - SERVER_HOST=<server-host>
+      - SERVER_PORT=<server-port>
+      - USERNAME=<username>
+      - PASSWORD=<password>
+      - DATA_DIR=<directory-path-to-sync>
+      - SEAFILE_UID=<your_uid>
+      - SEAFILE_GID=<your_gid>
+    volumes:
+      - <host-volume-path>:<directory-path-to-sync>
+```
+
 ## Environment variables:
  - `LIBRARY_ID=<your-library-id-here>`  ID of library to sync; multiple libraries could be separated by colon `:`
  - `SERVER_HOST=<server-host>`          Hostname of your seafile server, eg: seafile.example.com