Replace npm-run-all by npm-run-all2 in exemples

[Jayllyz]

Goals

npm-run-all is no longer maintained. Lighter, actively maintained alternatives exist.
-> https://github.com/es-tooling/module-replacements/blob/main/docs/modules/npm-run-all.md

Non-Goals

Background

https://e18e.dev/guide/cleanup.html

Proposal

Replace it by npm-run-all2.
I am interested in contributing.