A new type of shell.

Nu draws inspiration from projects like PowerShell, functional programming
languages, and modern CLI tools. Rather than thinking of files and data as
raw streams of text, Nu looks at each input as something with structure.
For example, when you list the contents of a directory what you get back is
a table of rows, where each row represents an item in that directory.
These values can be piped through a series of steps, in a series of commands
called a 'pipeline'.