Fix SendGrid and GitHub typos

[hugovk]

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.
• [n/a] I have added tests that prove my fix is effective or that my feature works
• [n/a] I have added necessary documentation about the functionality in the appropriate .md file
• [n/a] I have added in line documentation to the code I modified

Short description of what this PR does:

• Fix SendGrid typo
• Fix GitHub typo
• Fix some other typos
• Fix some inconsistent fullstops

If you have questions, please send an email to Sendgrid, or file a Github Issue in this repository.

[codecov]

Codecov Report

Merging #84 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master      #84   +/-   ##
=======================================
  Coverage   99.32%   99.32%           
=======================================
  Files           2        2           
  Lines         149      149           
=======================================
  Hits          148      148           
  Misses          1        1

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[hugovk]

Merge conflict resolved.

[hugovk]

Hello, is there anything extra I can do for this PR? Thanks!

[hugovk]

It's nearly time for the next Hacktoberfest! This PR has been approved, is anything else needed to merge it? Thanks!

[hugovk]

Closing these year-old PRs. Let me know if you're still interested and I can re-open. Thanks!