Change `entryPoints` to `entry` in `tsup.config.ts`

[joaopalmeiro]

Hi! 👋

I was checking the article on how to create an npm package (amazing resource, thanks!) and would like to suggest changing the entryPoints field to entry in the tsup configuration:

tt-package-demo/tsup.config.ts

Line 4 in 83de583

entryPoints: ['src/index.ts'],

The entryPoints field is deprecated: https://github.com/egoist/tsup/blob/v8.2.4/src/options.ts#L99-L103

What do you think? Let me if I can open a PR, please.