chore: add slot to allow additional course app plugin

.eslintignore

@@ -1,4 +1,6 @@
 coverage/*
 dist/
 node_modules/
-jest.config.js
+jest.config.js
+env.config.jsx
+example.env.config.jsx

.gitignore

@@ -26,3 +26,6 @@ temp/babel-plugin-react-intl
 
 # Messages .json files fetched by atlas
 src/i18n/messages/
+
+# environment js config
+env.config.jsx

example.env.config.jsx

@@ -0,0 +1,24 @@
+import WholeCourseTranslation from '@edx/course-app-translation-plugin';
+import { PLUGIN_OPERATIONS, DIRECT_PLUGIN } from '@openedx/frontend-plugin-framework';
+
+// Load environment variables from .env file
+const config = {
+  ...process.env,
+  pluginSlots: {
+    additional_course_plugin: {
+      plugins: [
+        {
+          op: PLUGIN_OPERATIONS.Insert,
+          widget: {
+            id: 'whole-course-translation-plugin',
+            type: DIRECT_PLUGIN,
+            priority: 1,
+            RenderWidget: WholeCourseTranslation,
+          },
+        },
+      ],
+    },
+  },
+};
+
+export default config;