docs: fix code snippet in README

[neerajgupta2407]

Code snipped provided is throwing error "TypeError: Object of type Email is not JSON serializable"

Fixes.:

1. Changed "to_email = To("test@example.com") " to to_email = To("test@example.com")
2. mail = Mail(from_email, subject, to_email, , content) to mail = Mail(from_email, to_email, subject, , content)

Fixes

A short description of what this PR does.

Checklist

• I acknowledge that all my contributions will be made under the project's license
• I have made a material change to the repo (functionality, testing, spelling, grammar)
• I have read the Contribution Guidelines and my PR follows them
• I have titled the PR appropriately
• I have 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 inline documentation to the code I modified

If you have questions, please file a support ticket, or create a GitHub Issue in this repository.

[codecov]

Codecov Report

Merging #878 into master will not change coverage by %.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #878   +/-   ##
=======================================
  Coverage   82.48%   82.48%           
=======================================
  Files          70       70           
  Lines        2312     2312           
  Branches      340      340           
=======================================
  Hits         1907     1907           
  Misses        206      206           
  Partials      199      199           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 8a53dc9...8724b73. Read the comment docs.

[childish-sambino]

@neerajgupta2407 Could you check the license box in the summary?

[neerajgupta2407]

@childish-sambino done.