fix install fastcore installation path

[jakobtroidl]

fix string in pip install command (replace git with https)

[schlegelp]

Thanks! This repo has effectively been superseded by fastcore-rs - I should probably indicate this somehow.

Are you actually using this?

[jakobtroidl]

Nevermind, I am using fastcore-rs now. I was confused what the difference is between this repo and the fastcore-rs repo. Maybe labeling this as deprecated would make sense ?