While vscode does not have API to show custom view in this way, it would be so cool if this plugin can show diagram in Hover, because it has quite small footprint..!
i don't know it this is possible.
but another vscode extension color-picker requires you to download election when install the extension, and display popup by creating another electron window.
atom-regex-railroad-diagrams plugin can show diagram below editor.
While vscode does not have API to show custom view in this way, it would be so cool if this plugin can show diagram in Hover, because it has quite small footprint..!