Add info with workaround to avoid MKL error

[tlienart]

Add the following in some format in the README

Finally another note, for mac users there is currently an issue with Julia on >=1.3 (unrelated to MLJ) which may make you see weird MKL errors when using MLJ with SckitLearn packages. There is a simple work around which is to install an older version of OpenSpecFun_jll; given that these _jll packages have weird version names, it’s a bit tricky to do and long story short I’ve forked the repo with the right version. In order to use it and avoid the errors, please just do Pkg.develop(PackageSpec(url="https://github.com/tlienart/OpenSpecFun_jll.jl")) in your MLJ environment. This will be a temporary workaround while the Julia folks solve the core issue (which might take a while).

• link to Discourse disscussion
• link to Package builder issue

[ablaom]

Done. Thanks @tlienart for all the work here.

[azev77]

@ablaom you prob are aware, but the README doesn’t mention some new models including LightGBM, unless you’re deliberately waiting