Sandbox watcher for`.arc` file generates expected directory structure

When running arc sandbox I typically have an editor open in another window. If I make any changes to the .arc file which describes all the routes then it would be nice if the sandbox could optionally generate the directory structure which arc would normally generate if you re-ran arc sandbox or arc init. This way, when doing development a change to the .arc file could automatically create any new directories which arc would expect and would generate anyway on successive executions of arc.

I recognize this might not be desired behaviour for all users. Not sure if this is good default behaviour but we could have a flag or some setting in a config file ignored by .gitignore that would let you set your local development behaviour. With an opt-in flag, usage would be something like

$ arc sandbox --generate

I can wrap this in another process to watch the .arc file but that has bad ergonomics.

See Slack Conversation

[ryanblock]

This has been a great thread, thank you @trevoro! Moving this into https://github.com/architect/architect/issues/763

[ryanblock]

Hmm, that’s a really good idea. May also present some issues, but I dig it.

I think to the original thrust of this issue: autoInit should prob be false (imo).