fix: 📝 Add example gif to README (#405)

feat: ✨ Sync timers & countdowns when page becomes visible again (#401)

* chore: ⬆️ Update time-sync

* refactor: ♻️ Migrate TimeProvider to a functional component

* feat: ✨ Sync timers & countdowns when page becomes visible again

* test: ✅ Extend page visibility tests

fix: 🏷️ Fix TimeProvider.children type

Adjusts the `children` prop type of `TimeProvider` to accept `ReactNode` in order to work with the default type of `React.FC` components.

feat: ⬆️ Support react@17

Updates the peerDependency version range to support react > v16.8 and react 17.

ci: download build to build folder

fix: switch to useStateWithDeps

fix: remove empty action for force update

fix: trigger publish for README update

fix(time-sync): Update time-sync for newest bugfix

fix(useCountdown): Ensure "until" is in the future