feat(cep): add documents for CI enhancement process

[dhiller]

What this PR does / why we need it:

Add initial drafts for documenting the CI enhancement process and add a template for describing a specific CI enhancement.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

Special notes for your reviewer:

/cc @dollierp

[kubevirt-bot]

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[kubevirt-bot]

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[kubevirt-bot]

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/lifecycle stale