Add front matter

website/docs/gateway/1-getting-started.md

website/docs/gateway/10-gateway-config.md

website/docs/gateway/11-gateway-services-config.md

website/docs/gateway/2-software-dependencies.md

website/docs/gateway/3-gateway-firewall.md

website/docs/gateway/4-gateway-port-forwarding.md

website/docs/gateway/5-clock-syncronization.md

website/docs/gateway/6-tcp-settings.md

website/docs/gateway/7-gateway-database.md

website/docs/gateway/8-gateway-tarballs.md

website/docs/gateway/9-transfer-creds.md

website/docs/gateway/_category_.json

website/docs/intro.md

website/docs/linux/_category_.json

website/docs/linux/add-user-account.md

website/docs/linux/change-timezone.md

website/docs/linux/get-ids.md

website/docs/linux/get-ips.md

website/docs/linux/logs.md

website/docs/linux/ufw.md