shellrepl -> env.pwd

[emmaccode]

Right now, the shellrepl is an actual Bash REPL tied to Base.run. Obviously, this is not the intended design but a placeholder. Instead, this cell going to use the methods established in the new 0.0.93 modules to change the Environment.pwd rather than -- whatever we are operating on otherwise. For root, the only command that will change is cd -- and the commands being run from that path.