React.JS Loading Screen and Preload All Assets

Need a developer who can create a loading screen for a React.JS application, while the loading screen and the loading animation is in place, the React web app should preload all assets such as image and video files. Need this done ASAP and cost efficiently.

The web app is located on GitHub:

https://github.com/jaeminkim-com/react-portfolio-site

Please send a pull request and will select freelancer based on the best solution and pricing, thank you.