per discussion in slack amphora-amp should use a different file name pattern to more harmoniously co-exist with component variations - it should be possible to specify a renderer and a variation as separate parts of a stylesheet filename.

currently AMP stylesheets are treated as component variations which makes them selectable options for other renderers, but we'd never want the AMP stylesheet to be used by the html renderer

Lots of components aren't allowed in AMP and our logs are full of warnings about them every time someone looks at a page. Is it OK to just change 'warn' to 'debug' here?

Need to replicate this functionality from Amphora HTML: clay/amphora-html#58

in amphora-html, componentVariation defaults to the component name if that property is not defined on the component instance. this logic is missing in amphora-amp, which can lead to un-intended consequences when developers are not aware of this discrepancy

It would be great if amphora-amp supported plugins in the same way that amphora-html does. Plugins export a render function that takes ref, data, locals and allows them to filter or move refs within the tree before they are rendered. Our use case would be for those components where we would want them in the head of the page, but amp only supports them in the body (namely, analytics components that we want to run before ads).

This was already implemented for amphora-html and would ideally be a similar PR.