Enhancement: Check how to add support for multiple asset folders

[estruyf]

In some SSGs you can have multiple asset folders. It would be good to be able to define multiple asset folders in the frontMatter.content.publicFolder setting.

Important: We need to check how images get inserted in the content. Paths can vary per asset folder.

{
	"frontMatter.content.publicFolder": [
		"public",
		{
			"path": "src/assets",
			"relative": true
		}
	]
}