Clean Up Env Documentation

[rawkode]

There were some conflicting configuration details, namely .env_sample,
and sendgrid.env. I've opted for .env_sample, as sendgrid.env
actually seemed to be incorrect.

Checklist

• I have made a material change to the repo (functionality, testing, spelling, grammar)
• I have read the [Contribution Guide] and my PR follows them.
• I updated my branch with the master branch.
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation about the functionality in the appropriate .md file
• I have added in line documentation to the code I modified

[SendGridDX]

All committers have signed the CLA.

[codecov]

Codecov Report

Merging #668 into v4 will increase coverage by 0.42%.
The diff coverage is 74.86%.

@@            Coverage Diff             @@
##               v4     #668      +/-   ##
==========================================
+ Coverage   84.35%   84.77%   +0.42%     
==========================================
  Files          36       35       -1     
  Lines         965     1156     +191     
  Branches      107      172      +65     
==========================================
+ Hits          814      980     +166     
+ Misses         93       90       -3     
- Partials       58       86      +28

Impacted Files	Coverage Δ
sendgrid/sendgrid.py	92% <ø> (+6.28%)	⬆️
sendgrid/helpers/mail/personalization.py	93.25% <100%> (+0.2%)	⬆️
sendgrid/helpers/stats/__init__.py	100% <100%> (ø)
sendgrid/version.py	100% <100%> (ø)
sendgrid/helpers/endpoints/ip/unassigned.py	15% <15%> (ø)
sendgrid/helpers/mail/mail.py	93.71% <50%> (-6.29%)	⬇️
sendgrid/helpers/stats/stats.py	82.19% <82.19%> (ø)
sendgrid/helpers/mail/__init__.py	100% <0%> (ø)	⬆️
... and 15 more

---

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[thinkingserious]

Hello @rawkode,

Thanks again for the PR!

It's HACKTOBERFEST! We want to show our appreciation by sending you some special Hacktoberfest swag. If you have not already, could you please fill out this form so we can send it to you? Thanks!

Team SendGrid DX

[thinkingserious]

Hello @rawkode,

Could you please merge this against our v4 branch? Thank you!

With Best Regards,

Elmer

[thinkingserious]

Hello @rawkode,

Thanks again for the PR!

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Please take a moment to checkout this link to find more issues to get you past the required threshold.

Also, please be sure that you have officially registered here.

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Team SendGrid DX