Section: hosting a relayer with a cloud provider

[aadam-10]

Description and context

Documentation (on book.wormhole.com or docs.wormhole.com) should be updated with information about the relayer engine. More context can be found in the linked milestone.

The scope of this task is to create a section that contains a start-to-end tutorial on how one might deploy and operate a relayer using a cloud provider such as AWS.

Definition of done

Changes are published.