Better support for SVG dataURL/inline in GraphQL (to reduce requests)

[mwt]

How many of you have gotten the following error at some point:

You can't use childImageSharp together with image.svg — use publicURL instead.

This error appears when you treat an SVG like any other image in Gatsby and try to insert it into your document using the standard fluid image workflow. The warning is actually great. It's highly descriptive and tells you how to get around the problem.

However, the solution of using publicURLs is not ideal. In many cases, the SVG is very small and should either be in-lined or converted to a data URL to reduce the number of requests. Adding a content or dataURL tag to GraphQL for files of the image/svg+xml mediatype (or even for all files) would help a lot with this.

The simplest solution might be to add a dataURL flag for all files. It's possible that there is already a great way to do this that I don't know about. I only started using Gatsby/react two days ago. So, I don't know a lot of the tricks.