Feature Request: SRI for CDN

Thank you for making this plugin available. I have used it for several years for caching and for rewriting static file links for my CDN, and it has worked very well.

I want to suggest a new feature that could be usefully added to the CDN functionality: subresource integrity (https://www.w3.org/TR/SRI/). It seems to me that the plugin is already selecting the static files that ought to have links rewritten, and that the plugin could, in addition, calculate the proper hash and add it to the link that it writes. This would kill two birds with one stone!. I wish I knew enough to do this myself, but since I don’t, I am suggesting it here.

Thank you!