Update docs/docs/migration-guide.mdx
Update docs/docs/migration-guide.mdx

Co-authored-by: Chris Kedzie <bccc5beedb304650d6db8f0ddc2b61fee2bd33ff@rasa.com>
RasaHQ/rasa_nlu,RasaHQ/rasa_nlu,RasaHQ/rasa_nlu