This PR changes `<Link>` to use `prefetch={false}` in the following
components:
1. Header
2. Sidebar
3. Docs header
4. Markdown content
This means that prefetch happens on hover of the link rather than page
load, and will reduce the amount of edge requests made from the app.
## Current Behavior
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## Expected Behavior
<!-- This is the behavior we should expect with the changes in this PR
-->
## Related Issue(s)
<!-- Please link the issue being fixed so it gets closed when this is
merged. -->
Fixes #
c7878533ed