didMount () {
    this.context.editorSession.getEditorState().addObserver(['document'], this._onDocumentChange, this, { stage: 'render', document: { path: this.getPath() } })
  }
Renders a text property. Used internally by different components to render
editable text.

@example

```js
$$(TextProperty, {
  path: [ 'paragraph-1', 'content']
})
```