[Feature] Expanded Node Shapes in Mermaid Flowcharts (v11.3.0+)

[hrvoj3e]

• Searched existing issues to avoid creating duplicates.
• Searched http://support.typora.io/ since it may be already implemented.

https://mermaid.js.org/syntax/flowchart.html#expanded-node-shapes-in-mermaid-flowcharts-v11-3-0

New Syntax for Shape Definition

Mermaid now supports a general syntax for defining shape types to accommodate the growing number of shapes. This syntax allows you to assign specific shapes to nodes using a clear and flexible format:

A@{ shape: rect }

This syntax creates a node A as a rectangle. It renders in the same way as A["A"], or A.