Description of problem:

We should specify in the "Requirements for OpenShift Data Science" section if the minimum requirements must be satisfied by using the default machine pool or the users can create a new machine pool which meets the reqs. Moreover, we should specify that it is not possible to combine resources from different machine pools, as described in this comment https://issues.redhat.com/browse/RHODS-1874?focusedCommentId=19129881&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-19129881 

The decision can be taken based on the discussion in RHODS-1874

Doc link:

https://pantheon.corp.redhat.com/pantheon/preview/latest/5ee38e4c-36d6-4519-b972-745388856c33