[Feature Enhancement] Support custom callout icons with Iconize plugin

[Oddward]

Iconize is a plugin that lets you use icons in various parts of the UI including file name prefix, folder name prefix, tabs, and more recently in the note content with a simple syntax: :PrefixedIconName:. E.g.

#### :RiSparklingFill: Summary

It supports any icon set — they're placed in an .obsidian/icons folder via the plugin settings or manually & loaded in live/rendered view — plus quick autofill suggestions with previews. It's shaping up to be the primary solution for icons in Obsidian — github link.

main problem

Admonitions requires an icon to be set in custom admonition settings, and from a limited set. It would be great if Admonitions supported other icon solutions like Iconize for the custom callout icons/title. This could be via:

• supporting the Iconize syntax in the icon: property & then rendering in title position

icon:  :RiSparklingFill:

• supporting syntax in the custom ad settings (maybe it can pull the svg?)

• option to have no custom ad icon and simply placing the icon we want in the title content.

````ad-summary
title:  :RiSparklingFill:  Heading text
icon:  

It somewhat works with md titles in codeblock atm
\````

Sample using markdown heading:

Optionally, if you go the disable icon route you could target the first icon child (svg or .cm-iconize-icon) to style it in the same way as the default icons.

I think this could greatly enhance admonitions without too much change on the plugin's end. Afaict, all that's needed is to place an icon call (:IconRef:) where the icon should be

notes

• attachment includes a couple small bugs being investigated atm, but gives an idea
• Iconize's symbol operator and icon name prefixes are not fixed
• currently, the icon name in plaintext is persistent except in reading mode — see Iconize issue #315