navbar refactor, tests for app and navbar

.vscode/launch.json

README.md

package-lock.json

package.json

src/App.css

src/App.test.tsx

src/App.tsx

src/components/admin/Navbar.test.tsx

src/components/admin/fragen/Question.tsx

src/components/admin/fragen/QuestionList.tsx

src/components/admin/navbar.tsx

src/components/admin/snack & co/Snack.tsx

src/components/user/homeComponent.tsx

src/index.tsx