[Tracking] Towards 1.0

Here are a number of steps we are currently working on for the next release, which should be tagged as breaking, to be safe, but probably not 1.0.

• Migration of MLJ Model Registry maintenance tools (#590)
• Remove all the transforms that have been ported to MLJTransforms.jl @ablaom self-assigned: https://github.com/JuliaAI/MLJModels.jl/pull/592
• Update the MLJ Model Registry
• This breaking change: https://github.com/JuliaAI/MLJTransforms.jl/issues/44 ?? Transfer the issue to MLJTransforms.jl
• Tag a new MLJModels release (as breaking)
• Upate MLJ to include MLJTransforms.jl and reexport its models (in a new version that requires the MLJModels version tagged in previous step). And also update the links in the documentation pointing to the wrong version of the models that have migrated across. https://github.com/JuliaRegistries/General/pull/138270
• Transfer from MLJModels all issues that apply to models now migrated to MLJTransforms.jl

For a 1.0 release, I propose the following additional item:

• Migrate the remaining models BinaryThresholdPrediction and the Constant (dummy) models to MLJBase.jl, or elsewhere.

This would make the sole function of MLJModels to host the Model Registry and provide users the tools to search it and load model code. I think then we would be very close to an MLJ 1.0 as well.

Review the unchecked migration item in this tracking issue and inspect the remaining BinaryThresholdPrediction and Constant models. Compare MLJBase.jl and the other MLJ packages named in the issue to determine the appropriate destination; the work is done when both models have been migrated and the 1.0 checklist item can be marked complete.