feat: add rendererRenderAsync

[s-light]

Description

allow for renderer.render access in the async way.

Linked Issues

fixes #3

Additional context

i have no experience in ts - so please review my code carefully!!
(i tried my best)

[s-light]

wow thanks @antfu !

[antfu]

Hey @s-light, I think I have to revert this right now. As you mentioned in
mdit-vue/mdit-vue#13, this breaks the plugins that replace render and causes unplugin/unplugin-vue-markdown#63 CI to fail. This will break the existing usages, so we can't ship this without a proper workaround.

[s-light]

yeah sorry for the work..

if mdit-vue/mdit-vue#13 is fixed - do you think it is fine then?
or are we locked-in with the possibility that other plugins replacing render ?

[antfu]

Yeah I think we should still support custom render function. To support your case, I think we should reuse our handling but not cascading them to support both cases

[s-light]

mdit-vue #13 is now fixed.

but if i understand you correct you think that we need to find another way to handle this?
as other plugins otherwise again fail?!
we could do this in the way that the special behavior is only used when the tokens option is set.
this way it is fine for existing users.