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 category to update.
The new title of the document page category.
Language code the title is written in. Omit it (or pass the default language) to update the base title; pass a non-default language to update that translation.