Cambiar ruta raiz de drupal composer

solo modifica los archivos composer.json el campo web-root y insaller paths

"drupal-scaffold": {
            "locations": {
                "web-root": "./"
            }
        },
        "installer-paths": {
            "core": ["type:drupal-core"],
            "libraries/{$name}": ["type:drupal-library"],
            "modules/contrib/{$name}": ["type:drupal-module"],
            "profiles/contrib/{$name}": ["type:drupal-profile"],
            "themes/contrib/{$name}": ["type:drupal-theme"],
            "drush/Commands/contrib/{$name}": ["type:drupal-drush"]
        }

el archivo autoload.php

return require __DIR__ . '/vendor/autoload.php';