Update how-to-read-environment-variables-from-nodejs.md with new `.env` guidance

[bmuenzenmeyer]

Update pages/en/learn/command-line/how-to-read-environment-variables-from-nodejs.md

This .env file addition should be a separate issue - otherwise this PR will be unresolved for longer.

Originally posted by @bmuenzenmeyer in #6132 (comment)

[ShashwatPS]

Hey i would like to work on this issue. Can you describe a little bit of what exactly is supposed to be updated in the md file ?

[AugustinMauroy]

@ShashwatPS this section in particular

[ShashwatPS]

I apologize for any inconvenience, but I noticed a discrepancy. The issue mentions a different file, while the reference you provided is for a file that seems to be different. @AugustinMauroy

[AugustinMauroy]

oops fail in copy paste
good link

[ShashwatPS]

Got it. Could you please assign me to this issue? Would like to work on it.

[AugustinMauroy]

Thanks for your interest. We don't assign tickets if we can help it. Feel free to submit a pull request if you have time.
Reference 🍪 https://www.redhat.com/en/blog/dont-lick-cookie