Reason for using `Zygote.@adjoint` instead of ChainRules `rrule` about daggerflux.jl

[DhairyaLGandhi]

Well, we don't really distinguish between AD frameworks as much as an API to use. Rather than using ChainRules, i think the right abstraction is to target AbstractDifferentiation.jl. that is an interface that ADs can hook into to export a uniform interface. Then any AD with any rule writing system can be used out of the box as long as they hook into the interface.

PS: you can write rrules and Zygote will pick them up automatically.

[DhairyaLGandhi]

We could definitely replace the occurrence of @adjoint with rrule though. That should be an easy fix.

[rejuvyesh]

I was asking because Zygote.accum was being used as well.