Added math.lerp to the math library documentation

[RobIux]

Updated _pages/library.md to include the recently added PR.

[vegorov-rbx]

Parameter names are atypical and thus incorrect.

Description doesn't match what the function is actually doing.

[RobIux]

Do I use a, b and t?

[vegorov-rbx]

Yes, you can check the https://rfcs.luau.org/function-math-lerp.html for definition details.

Your documented formula doesn't match how lerp is implemented in Luau, which can confuse the users about the function guarantees.
Although the real formula might also appear unfamiliar for why it's defined that way, but maybe it can be cleared up with a short second sentence.

[RobIux]

Alr I'll add those changes as soon as I can.

[RobIux]

I'm a bit confused with what you ment with "Your documented formula doesn't match how lerp is implemented in Luau" I've checked the way and it uses my formula.
I did add a note stating the early return if the value of t is 1 if that's what you were implying.