[DOC] Fix small typo

[georgejl7]

What does this implement/fix? Explain your changes.

A small grammatical error in the documentation

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[georgejl7]

@all-contributors please add @georgejl7 for documentation

[allcontributors]

@georgejl7

I've put up a pull request to add @georgejl7! 🎉

[TonyBagnall]

thanks