Entity view mode and form mode schema
First, form/user mode and form/user display isn't the same thing.

But the schema for all of them is in in core/config/schema/core.entity.schema.yml.

That said, I'm not sure why you want to build that file? Especially for a node type. Create the node type and the fields, configure the form and view displays in the UI, export it, add the files to your modules, don't. You don't have to build them yourself.