Kubeflow-Containers: Multi-stage build Strategy Documentation

[Souheil-Yazji]

Create documentation for strategy implementing results produced from #1991

[EveningStarlight]

Our CI should behave as follows:

• If a change is made at stage 6, only stage 6 and greater are rebuilt. This confirms that no conflicts arise in deeper depths.
• If a change occurs in the scripts, rebuilding of that stage and greater are required.
• No output files are used
• Each layer has a specific, well defined concern

[EveningStarlight]

7_Remove_vulnerabilities.Dockerfile isn't providing any fixes. Removing the version pinning leads to no new vulnerabilities on the build
Can be safely built into other layers

[EveningStarlight]

Test options for storing partial images. Registry or github artifacts

[EveningStarlight]

Workflow passes all tests

see codebase: StatCan/aaw-kubeflow-containers#702

[EveningStarlight]

Document outlining the overall plan

Staged Builds.docx

[EveningStarlight]