refactor: Switch to ESM

Checklist for new indicators

[ ] Indicator is documented and implemented by extending BigIndicatorSeries
[ ] A "faster" version of this indicator is implemented by extending NumberIndicatorSeries
[ ] Tests for getResult are present
[ ] Tests for highest and lowest result caching are present (if not already existent for base class)
[ ] Tests for error handling are present (if not already existent for base class)
[ ] Indicators (standard & faster version) are exposed in src/index.ts
[ ] Indicators (standard & faster version) are added to startBenchmark.ts
[ ] Indicator is listed in README.md