docs: add migration guide to 4.2

Author: mrholek

migration.md

@@ -1,3 +1,43 @@
-# Migration from version 3
+# Migration from version 4.1 to 4.2
+
+In version 4.2 we updated "react-scripts" to 5.0.0 and "react-router-dom" to 6.2.1
+
+Please check also React Router 6 migration guide https://reactrouter.com/docs/en/v6/upgrading/v5
+
+## Updated files
+
+- .browserlistrc
+- eslintrc.js
+- package.json
+- src/App.js
+- src/App.test.js
+- src/index.js
+- src/setupTests.js
+- src/components/AppBreadcrumb.js
+- src/components/AppHeader.js\
+removed `activeClassName: 'active',` from NavLink, because React Router Dom 6 doesn't support it
+- src/components/AppSidebarNav.js\
+removed `activeClassName: 'active',` from NavLink, because React Router Dom 6 doesn't support it
+- src/components/index.js
+- src/layout/DefaultLayout.js
+
+## Removed files
+
+- src/serviceWorker.js is removed use src/reportWebVitals.js
+- src/components/AppContent.js\
+  Routes map has been moved to src/App.js
+
+## Dependencies and devDependencies
+
+### Removed
+
+- @wojtekmaj/enzyme-adapter-react-17,
+- enzyme
+
+### Added
+
+- @testing-library/jest-dom
+- @testing-library/react
+- @testing-library/user-event
+- web-vitals
 
-https://coreui.io/react/docs/4.0/migration/v4/