Add back addon docs config

test-app/config/addon-docs.js

@@ -0,0 +1,8 @@
+'use strict';
+
+const AddonDocsConfig = require('ember-cli-addon-docs/lib/config');
+
+module.exports = class extends AddonDocsConfig {
+  // See https://ember-learn.github.io/ember-cli-addon-docs/docs/deploying
+  // for details on configuration you can override here.
+};

test-app/config/deploy.js

@@ -0,0 +1,27 @@
+'use strict';
+
+module.exports = function (deployTarget) {
+  let ENV = {
+    build: {},
+  };
+
+  if (deployTarget === 'development') {
+    ENV.build.environment = 'development';
+    // configure other plugins for development deploy target here
+  }
+
+  if (deployTarget === 'staging') {
+    ENV.build.environment = 'production';
+    // configure other plugins for staging deploy target here
+  }
+
+  if (deployTarget === 'production') {
+    ENV.build.environment = 'production';
+    // configure other plugins for production deploy target here
+  }
+
+  // Note: if you need to build some configuration asynchronously, you can return
+  // a promise that resolves with the ENV object instead of returning the
+  // ENV object synchronously.
+  return ENV;
+};