Enforce certain default nodes in schema

[sacha]

For those landing here, you might be interested in this other topic:

Design for constrained node content

I’m landing this on the master branch now. Here’s what you need to know to port your code: Schema definition is done differently now. The SchemaSpec class is gone, and you now pass a plain object to the Schema constructor, something like this: const mySchema = new Schema({ nodes: { // Node types in the schema doc: {type: Doc, content: "block+"}, paragraph: {type: Paragraph, content: "inline[_]*"}, text: {type: Text}, /* ... and so on */ }, groups: { // Groups referred to …