Confusing API names like every().day() & every().days()

Thanks for the API. It is really simple and easy-to-use.

We were using `schedule` module to trigger and run our periodic jobs. However, I was confused with the naming convention that `every().day()` will only once in that day whereas `every().days()` will run for all days. **In general, anything after `every()` is repetitive and human intuitive**. So, it's really confusing in the first place while using this method. Same follows for other dimensions like [(hour, hours), (minute, minutes), (week, weeks), (month, months)]

There was a lack of documentation explaining the clear difference between them. It would be **really awesome** if we change the names or providing better documentation. I'd **love to provide help** in this if needed.

Thanks again for the wonderful API.