chore: Fixed an incomplete sentence in contributing guide

[jbla484]

Description

I found an incomplete sentence while trying to learn how to make my first open source commit. I figured I'd fix it and help guide newcomers to include as much information as possible.

Specific Changes proposed

Fixed an incomplete sentence within the contributing readme.

Requirements Checklist

• Feature implemented / Bug fixed
• If necessary, more likely in a feature request than a bug fix
  • Change has been verified in an actual browser (Chrome, Firefox, IE)
  • Unit Tests updated or fixed
  • Docs/guides updated
  • Example created (starter template on JSBin)
• Reviewed by Two Core Contributors

[welcome]

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[codecov]

Codecov Report

Merging #8471 (8e6f56b) into main (cd2dac4) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #8471   +/-   ##
=======================================
  Coverage   82.71%   82.71%           
=======================================
  Files         113      113           
  Lines        7589     7589           
  Branches     1826     1826           
=======================================
  Hits         6277     6277           
  Misses       1312     1312           

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[welcome]

Congrats on merging your first pull request! 🎉🎉🎉