feat: revert paragon 23 upgrade (#662)

> [!IMPORTANT]
> ## Breaking Change released as Minor
> Consumers of this package must have support for Paragon 22.17.0
>
> Breaking changes in 22.17.0 can be found here:
> * https://github.com/openedx/paragon/releases/tag/v22.17.0
> Breaking changes for 22.0.0 can be found here:
> * https://github.com/openedx/paragon/releases/tag/v22.0.0

### Features
* Set peerDependency to v22.17.0
* Removes support for v21 and v23

Author: MaxFrank13

README.rst

@@ -8,10 +8,12 @@ frontend-component-header-edx
 Purpose
 ********
 
-This is the standard edX header for use in React applications. It has two exports:
+This is the standard edX header for use in React applications. It has four exports:
 
 - **default**: The Header Component
 - **messages**: for i18n in the form of ``{ locale: { key: translatedString } }``
+- **LearnerHeader** Header component for the Learner MFE
+- **StudioHeader** Header component for Studio
 
 Cloning and Startup
 ===================
@@ -57,6 +59,13 @@ Development
 - Start the example server `npm start`
 - Visit http://localhost:1234
 
+Contributing
+============
+
+Since the exports from this package are used throughout many micro-frontends, it is important that updates are communicated effectively throughout the organization.
+
+When making updates to this repo, pull requests should be shared on the **#edx-fedx** Slack channel for soliciting review.
+
 License
 =======
 

example/index.js

@@ -1,6 +1,3 @@
-import 'core-js/stable';
-import 'regenerator-runtime/runtime';
-
 import React, {StrictMode} from 'react';
 import { AppContext, AppProvider } from '@edx/frontend-platform/react';
 import { initialize, getConfig, subscribe, APP_READY } from '@edx/frontend-platform';