Update `with-temporal` example to latest version of Temporal TS SDK API.
AFAICT, next.js doesn't yet support `type: "module"` in root `package.json`, so I added a nested `package.json` for Temporal.
## Documentation / Examples
- [x] Make sure the linting passes by running `yarn lint`
Co-authored-by: Balázs Orbán <18369201+balazsorban44@users.noreply.github.com>