refactor: move backup, restore, s3fs tasks in pkg folder

examples/docker-compose.yaml

@@ -0,0 +1,16 @@
+version: "3"
+services:
+  pg-bkup:
+    image: jkaninda/pg-bkup
+    container_name: pg-bkup
+    command:
+      - /bin/sh
+      - -c
+      - bkup --operation backup --dbname database_name
+    volumes:
+      - ./backup:/backup
+    environment:
+      - DB_PORT=5432
+      - DB_HOST=postgress
+      - DB_USERNAME=userName
+      - DB_PASSWORD=${DB_PASSWORD}