nf() function description inadequate

[michalrzak]

Issue description

nf() function reference could use a better description. As of now the text says:

Utility function for formatting numbers into strings. There are two versions: one for formatting floats, and one for formatting ints. The values for the digits and right parameters should always be positive integers. The left parameter should be positive or 0. If it is zero, only the right side is formatted.

This text only states that an int and a float version is existent. Nowhere is it explained how those are different. Referring to this description a call like nf(float, int) would be valid. This call however is not functional as passing num as a float variable requires to specify a left and right parameter (so the call has to be nf(float, int, int)).

This could be confusing to beginner programmers.

URL(s) of affected page(s)

https://processing.org/reference/nf_.html

Proposed fix

In my opinion ideally, in line with single responsibility, these would be two functions.

However an extended description should also do the trick. The text could be extended by a paragraph similar to:

When num is a variable of type float the call becomes nf(num, left, right). left represents the formatted number left of the decimal point and right represents the formatting right of the decimal point.

Alternatively it could be made clear in the Syntax and Parameter section which call allows which parameters.

nf(numf, left, right) nf(numsf, left, right)

numf = float: the number to format numsf = float[]: the numbers to format