Edits under "motherboard" and "Input and Output"

[DESR95]

"An" at beginning of sentence under input and output, "The" at beginning of sentence under motherboard.

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Closes #XXXXX

[cmccormack]

Thank you for your contribution. At this time we have decided not to merge your pull request. We welcome future pull requests from you.

Explanation
The changes in this PR conflict with the master branch. The file edited in this commit has since been edited and/or moved. Please feel free to update your fork of the freeCodeCamp master branch and submit your edits in a new Pull Request.

Happy Coding!