How to get pivotModelTransformerManager?
import pivotModelTransformerManager from 'fontoxml-pivot-model/src/pivotModelTransformerManager.js'
The pivot model manager manages transformers which translates between DOM structures and pivot models.
Currently, this is used for pasting HTML to Fonto.
Register a contextual transformer.
Contextual transformers can be used to influence import behavior on certain positions by only registering them of the import position matches with a certain selector.
Register a part of the transformerConfiguration