ability to "pad" a number in formatting

See also: https://github.com/adamwdraper/Numeral-js/issues/123

Which references this implementation: https://gist.github.com/resident-uhlig/7906919

I don’t love the syntax #N# but at least it works!

[atuttle]

FWIW, I’ve worked with other languages/libraries that use the number of digits in the format string as if they were significant-digits; so:

5.format('000')
=> 005

15.format('000,000.00')
=> 000,015.00

IMO that would be the best possible implementation (seems very clean to me) but I’m not sure how feasible it is to work that into the current formatting implementation, or if it would break any existing expectations at all.

[BenjaminVanRyseghem]

That’s indeed the case.

I will add documentation with the next release.

But if you want to propose a PR before, feel free 😄