Deploy boards page contains instructions to setup logs, but the instructions can be used for setting up a cluster

Objective

Move the instructions for deploy boards to a more general location, as they can be used to setup clusters and view their logs.

https://gitlab.com/gitlab-org/gitlab/blob/master/doc/user/project/deploy_boards.md#L58

Original discussion

The following discussion from !20204 (merged) should be addressed:

• @mrincon started a discussion: (+1 comment)

  The deploy boards page contains all the instructions to setup, but now, the instructions are not just specific to "deploy boards"