If you're looking for the live site, you can find it at cadence-lang.org.
cadence-lang.org uses Docusaurus2.
Requirements:
To run the site locally, enter the following commands into a terminal window:
git clone https://github.com/onflow/cadence-lang.org.git
cd cadence-lang.org
npm i
npm run start
open "http://localhost:3000"