Add prose option

[vabatta]

Hi, as the title says it would be nice to have the typography set in the plugin to be used for external content styling with f-prose class like the https://unocss.dev/presets/typography.

[mortona42]

I just started working with this plugin. I am thinking we could do this as an uno shortcut, or @apply the fluid type class on the prose class.

A plugin setting would be nice too though.