adds feature spécified in bracoxide#6
```
$ echo {01..10}
01 02 03 04 05 06 07 08 09 10
$ echo {1..010}
001 002 003 004 005 006 007 008 009 010
```
I'm going to update the examples, but I'm currently on mobile. Will land
in a couple of days.
These sub-crates form both the foundation for Nu and a set of plugins which extend Nu with additional functionality.
Foundational libraries are split into two kinds of crates:
Core crates - those crates that work together to build the Nushell language engine
Support crates - a set of crates that support the engine with additional features like JSON support, ANSI support, and more.
Plugins are likewise also split into two types:
Core plugins - plugins that provide part of the default experience of Nu, including access to the system properties, processes, and web-connectivity features.
Extra plugins - these plugins run a wide range of different capabilities like working with different file types, charting, viewing binary data, and more.