Is setFieldsOnGraphQLNodeType deprecated ?

[tonyhallett]

Both https://github.com/gatsbyjs/gatsby/blob/master/docs/docs/schema-generation.md#3-legacy-schema-customization and https://www.gatsbyjs.com/docs/schema-inference state that it is deprecated.

Yet https://www.gatsbyjs.com/docs/reference/config-files/gatsby-node/#setFieldsOnGraphQLNodeType does not mention that it has been deprecated. It has not been marked as deprecated in the typescript. There are gatsby plugins that are still using it - for instance the gatsby-plugin-page-creator