Breaking up is hard to do, but pouring your heart out on paper is rather awkward. There is really no need for any other information in your resignation letter (including a reason __ which is completely optional). No effusive template and formatting effort is required. This is not a letter that is going to be hanging on anyone's wall, and it probably won't even be filed away!
Do You Really Need to Write a Resignation Letter? Why Write a Resignation Letter? Do you really need to write a formal resignation letter? The short answer is that most of the time, no letter of resignation is necessary. Many people do believe that as an employee you need to formally resign from a job by writing a formal resignation letter to your current employer.