Consider removing package-lock.json from template

[tormi]

We don't have composer.lock committed to the template, because it would be outdated pretty soon. Could we also consider removing package-lock.json from the repository? That would reduce the maintenance resources needed significantly.

[tormi]

Also, we're in D9 era now, package.json ;)

  "name": "wunder-d8-starter",
  "version": "1.0.0",
  "description": "",
  "keywords": [
    "Drupal 8",
    "Eslint",
    "Stylelint"
  ],