Great asked question @greathayat we appreciate your interest in HTML 5
You can use the platform WordPress and simply can write URDU in WordPress. You need to install URDU font in your computer, I would recommend you to install
Jameel Noori Nastaleeq Urdu font, which almost URDU news website doing it. Unlike, can install Pak Urdu Installer in your computer then press Alt + Shft then you will be able to write URDU directly from your computer keyboard.
Important one thing, please use the RTL (Right to Left) friendly theme on your website.