NextJS deploy script

This script is for self-hosting a NextJS app with NGINX using PM2 with a 'blue green workflow' that gives:

• Zero downtime – no downtime between deployments
• If the build fails, use the working version
• Auto Deploy - 'git push' to main
• Logs – See the View all the build logs and see build progress in GitHub actions

Here's the script - ideally triggered from a GitHub action.

Here's a guide that shows you how to use it and set up blue green deployment on your server.