Add an ArkScript tutor in the CLI

ArkScript has documentation, a tutorial and resources on a multitude of subjects on it website, but you need an internet connection to access them, and to switch to your REPL or the online playground to try things out.

It would be nice to have an ArkScript tutor, like vim or helix, that could be launched from the CLI, eg using the REPL?

It should be referenced in the help message of the cli, and on the website.

I'd like to see something with chapters, like the language tutorial we have, where you can try some code and see what it does, with the tutor explaining common errors.

Start by reading the existing CLI help, REPL, website resources, and language tutorial to understand how entry points and tutorial content are organized. Define the tutor's chapters, runnable examples, common-error explanations, and CLI launch path; it is done when it works offline and is referenced in both CLI help and the website.

Written by the indexing model from the issue text.