Create up to date CR reference images

[tuminoid]

Create up to date CR reference images. In #499, very old (5y+) images and crs_reference.md is removed, but we liked the graphics showing the relations.

This would optimally be something that can be part of the Metal3 book, perhaps in Developer section, and perhaps something more maintainable, like Mermaid graphs (ie. Markdown).

[metal3-io-bot]

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[tuminoid]

/kind documentation