Fix typo: "The Pragmatic Developer" to "The Pragmatic Programmer"

[gustavothecoder]

Pull Request Checklist

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• [x] I have read the Contributor Guidelines.
• [x] I have not directly copied text from another location (unless explicitly indicated as a quote) or violated copyright.
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• [x] I am happy to have my changes merged, so that I appear as a contributor, but also the text altered if required to keep the language consistent in the project.

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[dwmkerr]

Thank you @gustavothecoder