Re-add blockquotes in Windows build instructions.
Re-add blockquotes in Windows build instructions.

Also fix the switchover date.

BUG=none
R=brucedawson@chromium.org

Review URL: https://codereview.chromium.org/1849143004

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#384941}

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