Fix the killing of processes in monorepo

[jplhomer]

In #443, we added a -k to the dev script in our demo-store. @frandiox probably knows why for sure, but my guess is that we wanted to prevent stray processes from running when one of them fails.

This works fine when you're running npm run dev from within the demo-store template itself! BUT: when you run it as part of the turbo monorepo dev command, shit breaks with no real error. I'm guessing this is related to a false positive within concurrently, perhaps due to turbo or due to the preceding && command.

demo-store:dev: > demo-store@0.0.0 dev:css
demo-store:dev: > postcss styles --base styles --dir app/styles -w
demo-store:dev:
demo-store:dev: npm ERR! Lifecycle script `dev` failed with error:
demo-store:dev: npm ERR! Error: command failed
demo-store:dev: npm ERR!   in workspace: demo-store@0.0.0
demo-store:dev: npm ERR!   at location: /Users/jasonkurian/src/github.com/Shopify/h2/templates/demo-store

https://github.com/open-cli-tools/concurrently#usage

Anyway, this seems to fix it.

[JaKXz]

Thanks Josh!

[frandiox]

Funny thing is that I was the one removing -k months ago because I found this bug as well... but I forgot about it 😅
I added it back because when calling process.exit(1) in the CLI after finding an error (e.g. when a config value is wrong), concurrently keeps the CSS/Tailwind process running.

Glad the full --kill-others-on-fail flag does the trick 👍