Update README.vn.md file

[kjvfghkrgs]

Update README file, add easy command to install script

Open /root folder

cd /root

Auto download, set permission and install with only one command

curl -sO https://raw.githubusercontent.com/Paul-Reed/cloudflare-ufw/master/cloudflare-ufw.sh && chmod +x cloudflare-ufw.sh && ./cloudflare-ufw.sh

[Paul-Reed]

Thanks for the PR, however;

1. Your fork is 4 commits behind my repo, and you should Sync fork first before creating a PR.
2. Although you've titled this PR Update README.vn.md file, your PR would over-write my README.md which is in English, and not the Vietnamese README.vn.md file.

[Paul-Reed]

No reply, so closing PR.