Insert a Mermaid diagram in `docs/contributing/core/package-dependencies.md`

[stevepiercy]

Links of affected pages in Plone Documentation, if any.

No response

Description

Insert a Mermaid diagram in docs/contributing/core/package-dependencies.md.

@jensens said he would generate one, so I've assigned him, but anyone can take it on.

See https://github.com/plone/documentation/pull/1671