Add chardet to env.yml

[eroell]

Hey there,

thanks for this effort! Trying to make it run, and seems that chardet is not in the env.yml, and isn't a dependency of the packages in there, but is used for running 1_{dataset}.py

chardet 5.2.0 could work, but I see you do strict pinning in the yml, maybe safer for you to specify which one works for sure instead of me making the small PR with just guessing this version