Expose remark-rehype options in config

[JakeIsMeh]

Is your feature request related to a problem? Please describe

I'm trying to configure remark-rehype, particularly for footnotes. parseMarkdown() from @nuxtjs/mdc directly exposes this ability, but looking at src/runtime/transformers/markdown.ts, it seems that I cannot do it because the config object is spread at the top rather than the bottom of the object passed to parseMarkdown() which means it gets overridden:

content/src/runtime/transformers/markdown.ts

Lines 29 to 44 in c769bf8

	const parsed = await parseMarkdown(content as string, {
	...config,
	highlight: highlightOptions,
	remark: {
	plugins: config.remarkPlugins
	},
	rehype: {
	options: {
	handlers: {
	link: link as any
	}
	},
	plugins: config.rehypePlugins
	},
	toc: config.toc
	})

Additionally, this is not exposed in the module configuration for @nuxt/content which results in a type error when attempting to declare the config.

Describe the solution you'd like

I'd like for something like rehypeOptions to be exposed in the module config that is passed directly to parseMarkdown()

Describe alternatives you've considered

I tried directly configuring @nuxtjs/mdc rather than @nuxt/content but given that it uses parseMarkdown() directly it was never going to work.

Additional context

• I am willing to submit a PR for this feature request