All mutations have exactly one input field called input with a unique input and return type. This is useful to write mutations with variables, so there is always one single variable per mutation. This makes it easier to use and reuse them.
The ID of the guideline document page to update.
Language code the title is written in. Only meaningful together with title. Omit it (or pass the default language) to update the base title; pass a non-default language to update that translation.
The new title of the document page.
The new heading of the document page.
The new subheading of the document page.