Remove extra backtick from README.md

[NorseGaud]

Unsure how that got in there :)

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[gmlewis]

Thank you, @NorseGaud !
LGTM.
Merging.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.88%. Comparing base (2b8c7fa) to head (c34b18b).
Report is 49 commits behind head on master.

Additional details and impacted files

@@ Coverage Diff @@## master #3158 +/- ##
==========================================
- Coverage 97.72% 92.88% -4.84% 
==========================================
Files 153 170 +17 Lines 13390 11458 -1932 ==========================================
- Hits 13085 10643 -2442 - Misses 215 724 +509 - Partials 90 91 +1 

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