Update README.md

[jaymmodi]

Fix typo in readme. I think author originally wanted to narrow bufferB and not bufferA.

Fixes #<issue_number_goes_here>

It's a good idea to open an issue first for discussion.

• Tests pass
• Appropriate changes to README are included in PR

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[karllessard]

Thanks @jaymmodi , sorry for the delay I just noticed that PR ;)