CONTRIBUTING.md Grammerly verification

[mrinal1209]

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

Short description of what this PR does:

• Grammerly verified

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[SendGridDX]

Thank you for your submission, we really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[thinkingserious]

Since there has been no activity on this issue since March 1, 2020, we are closing this issue. If you are still interested in moving this PR forward, please feel free to reopen. Thank you!