Add "full screen" (⛶ icon) support for diagrams renderings

[yarikoptic]

Context

Thank you for supporting mermaid diagrams! Very handy! But quite often diagrams come out to be loaded and hard to see in the real estate they are allowed for with sidebars etc.

Description

It would be great if there was icon (like ⛶ ) in the corner of the diagram with ability to open diagram in some modal windows zoomed in full screen of the browser.

Related links

• https://squidfunk.github.io/mkdocs-material/reference/diagrams/

Use Cases

• embedding large diagrams like the one we propose ATM in Provide mermaid diagram of relation between BIDS schema, specification and validators bids-standard/bids-website#626

Visuals

our diagram ATM is

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• I have verified that my idea is a change request and not a bug report.
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[squidfunk]

Thanks for suggesting. We're currently in feature freeze due to the foundational work we're focusing on, so we're not considering this change. Closing as out of scope and duplicate of #5208, but we might re-evaluate in the future.

However, another user wrote an MkDocs plugin that implements this behavior, so you can start using it right now ☺️