provide example of how to upload a pre-made image to the cloud using a pkg

[eyberg]

https://github.com/nanovms/ops-examples/issues/40 https://github.com/nanovms/ops/pull/488

https://github.com/nanovms/ops/pull/645

in the past one would use 'ops load' and it creates an image on the fly - this is troublesome for some users though that don't want/can create images on the fly - for instance if you have a native node module that needs to be compiled on a linux system but want to deploy from a mac - this faciliates that

ops load sample-node-js, got the image built locally
2. ops sync node -t gcp to upload that image to GCP
3. ops instance -i node -t gcp ... and i managed to access

[eyberg]

https://github.com/nanovms/ops-documentation/issues/125