Add docs for downloading prebuilt binaries from CIPD

NOTRY=true
DOCS_PREVIEW= https://skia.org/?cl=13101
Bug: skia:
Change-Id: Iefa8070c65881ff8c05a3b88aa8385fcc1a427ff

Change-Id: Iefa8070c65881ff8c05a3b88aa8385fcc1a427ff
Reviewed-on: https://skia-review.googlesource.com/13101
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Kevin Lubick <kjlubick@google.com>
1 file changed