chore: Add .env_sample

[CorneliusIV]

This connects to #30

[SendGridDX]

Thank you for your submission, we really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
1 out of 2 committers have signed the CLA.

✅ CorneliusIV
❌ mbernier
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[thinkingserious]

Hello @CorneliusIV,

Thanks again for the PR!

We want to show our appreciation by sending you some swag. Could you please fill out this form so we can send it to you? Thanks!

Team SendGrid DX

[mbernier]

@CorneliusIV
If you are interested, we would love the opportunity to talk to you about Hacktoberfest and our API libraries.

Our agenda would be: Explore what you liked and is there anything we can do to improve?

You can grab a time on my calendar that works for you and we can have a chat on Google Hangout or Skype. If you prefer, you can email me using my GitHub username at my company’s domain.

Thank you so much,

Matt Bernier - @mbernier - SendGrid Developer Experience Product Manager
Elmer Thomas - @thinkingserious - SendGrid Developer Experience Engineer
@sendgrid

[CorneliusIV]

@mbernier Thank Matt, I will put something on your calendar.