we need to be able to pass in a custom cname into the config:

https://github.com/cloudinary-devs/gatsby-source-cloudinary/blob/3695b8afb8214f8e966a55f1ea0b233c14ac3476/plugin/utils.js#L23

you may already know this, so bear with me if im repeating what you know, but this appears to be configured via pluginOptions:

https://github.com/cloudinary-devs/gatsby-source-cloudinary/blob/3695b8afb8214f8e966a55f1ea0b233c14ac3476/plugin/gatsby-node.js#L115

so i believe we need to make it available via the schema:

https://github.com/cloudinary-devs/gatsby-source-cloudinary/blob/3695b8afb8214f8e966a55f1ea0b233c14ac3476/plugin/gatsby-node.js#L10

in order for someone to be able to use this and pass it in