Before running the website, make sure you've run the following:
git clone https://github.com/facebook/react-native.git
cd react-native
npm install
The first time, get all the website dependencies loaded via
cd website
npm install
Then, run the server via
npm start
open http://localhost:8079/react-native/index.html
Anytime you change the contents, just refresh the page and it's going to be updated.
cd website
npm run publish-website