Update crontab for multiple execution times and add docker-compose configuration for gsheet-bot service

crontab

@@ -1 +1 @@
-0 8 * * * python /app/main.py >> /var/log/cron.log 2>&1
+0 8,13,18 * * * python /app/main.py >> /var/log/cron.log 2>&1

docker-compose.yml

@@ -0,0 +1,7 @@
+version: '3.8'
+services:
+  gsheet-bot:
+    build: .
+    restart: unless-stopped
+    volumes:
+      - ./credentials.json:/app/credentials.json:ro