template.composer.json

{
  "type": "project",
  "repositories": {
    "drupal": {
      "type": "composer",
      "url": "https://packages.drupal.org/8"
    },
    "asset-packagist": {
      "type": "composer",
      "url": "https://asset-packagist.org"
    }
  },
  "require": {
    "composer/installers": "^1.2.0",
    "cweagans/composer-patches": "^1.6.4",
    "oomphinc/composer-installers-extender": "^1.1",
    "wikimedia/composer-merge-plugin": "^1.4.1"
  },
  "require-dev": {},
  "extra": {
    "enable-patching": true,
    "installer-types": ["bower-asset", "npm-asset"],
    "installer-paths": {
      "[drupal-root]/core": ["type:drupal-core"],
      "[drupal-root]/modules/contrib/{$name}": ["type:drupal-module"],
      "[drupal-root]/modules/custom/{$name}": ["type:drupal-custom-module"],
      "[drupal-root]/profiles/contrib/{$name}": ["type:drupal-profile"],
      "[drupal-root]/profiles/custom/{$name}": ["type:drupal-custom-profile"],
      "[drupal-root]/themes/contrib/{$name}": ["type:drupal-theme"],
      "[drupal-root]/themes/custom/{$name}": ["type:drupal-custom-theme"],
      "[drupal-root]/libraries/{$name}": ["type:drupal-library", "type:bower-asset", "type:npm-asset"],
      "drush/contrib/{$name}": ["type:drupal-drush"]
    },
    "merge-plugin": {
      "include": [
        "[drupal-root]/modules/custom/*/composer.json"
      ],
      "replace": false,
      "ignore-duplicates": true
    },
    "patches": {}
  },
  "minimum-stability": "dev",
  "prefer-stable": true
}