Create a cron job that will periodically execute the provided handler callback based on the specified schedule.

Deno.cron("sample cron", "*\/20 * * * *", () => {
  console.log("cron job executed");
});

backoffSchedule option can be used to specify the retry policy for failed executions. Each element in the array represents the number of milliseconds to wait before retrying the execution. For example, [1000, 5000, 10000] means that a failed execution will be retried at most 3 times, with 1 second, 5 seconds, and 10 seconds delay between each retry.