The new fillBackground.seed prop should be added to the docs, based on the next-cloudinary change

The changes need to be made to the fillBackground table in the following files, as well as the examples you can find under those tables. The markdown here is very similar to the next-cloudflare ones, so should be easier

• packages/docs/src/content/docs/components/image/configuration.mdx
• packages/docs/src/content/docs/helpers/getcldimageurl/configuration.mdx