allow arbitrary fields on NodeSpec and MarkSpec (#36062)
allow arbitrary fields on NodeSpec and MarkSpec (#36062)

* allow null on attrs for NodeType.create methods

* allow arbitrary fields on NodeSpec and MarkSpec

dsebastien/DefinitelyTyped,markogresak/DefinitelyTyped,mcliment/DefinitelyTyped,georgemarshall/DefinitelyTyped,georgemarshall/DefinitelyTyped,dsebastien/DefinitelyTyped,georgemarshall/DefinitelyTyped,georgemarshall/DefinitelyTyped