Update package onboarding docs for bb-common

Motivation

bb-common has now been validated as an appropriate glue for packages needing to integrate with Big Bang. With this milestone, the package onboarding docs need to be updated to reflect the new onboarding process with bb-common in the mix.

Acceptance Criteria

• The package onboarding documentation explains how to use bb-common to integrate a new package with Big Bang
• A full review of all docs must be done to confirm any mentions of previous status-quo configuration primitives are revised to match the bb-common patterns