message: adapt empty document
diff: @@ -12,6 +12,7 @@ import { TextPluginOptions } from './types'
  export const defaultNode = 'paragraph'
  export const textState = scalar<ValueJSON>({
  + // @ts-ignore: slate.js has changed data format and typings are out-dated
  document: {
  nodes: [
  {
  @@ -19,13 +20,7 @@ export const textState = scalar<ValueJSON>({
  type: defaultNode,
  nodes: [
  {
  - object: 'text',
  - leaves: [
  - {
  - object: 'leaf',
  - text: ''
  - }
  - ]
  + object: 'text'
  }
  ]
  }
  