Expanded and Closed versions of Flowchart subgraphs

[JohnAtChetwood]

Proposal

Sometimes for different audiences, I would like to render a flow chart without some subgraphs cluttering up the diagram.

• A way to quickly mark a subdiagram as closed, so it is rendered in a small format, maybe a square with some text.
• As a software engineer this makes it easier to render a diagram to quickly highlight the area I have been working on.
• As an addition to this, there could be a "closed" section in the subdiagram that is used to give the config of how to render the closed subgraph (if different to the default behaviour).

This is a static change and to do with how the diagram is rendered given the syntax. note it is similar to #1123 but this is about subdiagrams and not about interactive behaviour. It is about being able to to modify syntax quickly to render the diagram differently.

Thanks.

Example

Some possible thought of how this could look:
Here

flowchart TB
    c1-->a2
    subgraph one closed
    a1-->a2
    end
    subgraph two
    b1-->b2
    end
    subgraph three
    c1-->c2
    end

if i wanted to add text different to the default or do something different, i could optionally add a closed section:

flowchart TB
    c1-->a2
    subgraph one closed
    a1-->a2
    closed "new text when closed"
    end
    subgraph two
    b1-->b2
    end
    subgraph three
    c1-->c2
    end

Screenshots

No response