Add readme with docker-compose example file

Readme.md

@@ -0,0 +1,21 @@
+Docker Compose Example
+
+```yml
+version: "3"
+services:
+  paper:
+    image: "pandacubefr/paper:(version)"
+    container_name: (server name)
+    stdin_open: true # docker run -i
+    tty: true        # docker run -t
+    user: "1000:1000" # uid and gid of owner of working dir 
+    environment:
+      - MAXMEM=2048M # Java max heap size
+    restart: always
+    volumes:
+      - .:/data/workdir
+      - /etc/timezone:/etc/timezone:ro
+      - /etc/localtime:/etc/localtime:ro
+    ports:
+      - "0.0.0.0:(port):25565"
+```