Early access on next.config.ts

[devjiwonchoi]

https://github.com/devjiwonchoi/next-config-ts-preview

This is an early access of next.config.ts I've worked on #57656.
If interested, please try it out and send feedback here so this feature can have fewer bugs. 😆

To integrate into your working project, run the following commands:

pnpm add -D next-config-ts-preview
pnpm next-config-ts-preview

NOTE: The following scripts are modifying the next package in your node_modules. To undo them, reinstall the dependencies.