Fix nesting of Laptop Donations section

Why is this change being made?

This MR only fixes Markdown formatting:

• Fix nesting of the Laptop Donations section and its two child sections from h2 to h3 and from h3 to h4, because in its current state it looks like all the headings below it are related to the topic of donations (marked in red).
• Fix nesting of several other sections from h5 to h4 because they're nested under a h3. Unnecessarily using a higher heading level makes the headings less visible in text (marked in green).
• Additionally, the Web IDE trimmed extra whitespace from some other lines. I didn't intend that, but decided to keep it.

Before	After

Author Checklist

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• Added a description to this MR explaining the reasons for the proposed change, per say why, not just what
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