[Feature]: Ergonomic PATH variable

[MrPicklePinosaur]

What would you like to see added?

Introduce some helper utilities for interacting with the $PATH environment variable. Traditionally in other shells, we would append to PATH using string formatting, resulting in potential for user error

export PATH="$PATH:some/other_path"

we should expose an interface for us to dynamically add/remove items in path and it will automatically update the corresponding environment variable.