chore: 🤖 add support for API_HOST build-time config

addons/api/addon/adapters/application.js

@@ -5,6 +5,13 @@ import { get } from '@ember/object';
 export default class ApplicationAdapter extends RESTAdapter {
   // =attributes
 
+  /**
+   * Sets host to the `api.host` string in the application's config,
+   * if set.
+   * @type {string}
+   */
+  host = get(config, 'api.host');
+
   /**
    * Sets namespace to the `api.namespace` string in the application's config,
    * if set.