docs: remind to add S3 links to GitHub Releases entries (#956)
docs: remind to add S3 links to GitHub Releases entries (#956)

We are now going to be adding links to files published in AWS S3 in
GitHub Releases, so that people used to finding pre-built versions of
the software in GitHub Releases will be re-directed to the right place,
while we still keep the analytics advantages that S3 provides us.

Signed-off-by: Juan Cruz Viotti <4148f5869aa1bcd7efd85b513a5874967e585032@openmailbox.org>
resin-io/herostratus,resin-io/etcher,resin-io/resin-etcher,resin-io/etcher,resin-io/resin-etcher,resin-io/etcher,resin-io/herostratus,resin-io/etcher,resin-io/etcher