support for in-place operations for redden adn deredden (redden! & deredden!)?

[m4ttes4]

I was wondering if there are plans to include in-place versions of the main functions, specifically redden! and deredden!.

Currently, the implementation of redden creates a new array for every call:

redden(law::ExtinctionLaw, wave::Real, flux; Av = 1) = flux * 10^(-0.4 * Av * law(wave))

In scenarios where we are processing large spectra or multiple lines of sight, avoiding the allocation of a new flux array by modifying the existing one in-place would significantly improve performance and memory efficiency.

A possible implementation for the in-place version could look like this:
function redden!(law::ExtinctionLaw, wave, flux; Av = 1) flux .*= 10 .^ (-0.4 .* Av .* law.(wave)) return flux end

[abhro]

Created #84 to address it. Please feel free to chime in!

[abhro]

Spectra.jl seems to implement it
https://github.com/JuliaAstro/Spectra.jl/blob/7dbec7950e31c7b61a519dfede2aadd4ec2127c5/src/transforms/redden.jl#L9-L13

[icweaver]

Having that functionality here and then just calling it from Spectra.jl sounds great to me, thanks!