Extend v2.3 migration guide (#5653)
Extend v2.3 migration guide (#5653)

* Extend preloaded vocab section

* Add section on tag maps
spacy-io/spaCy,explosion/spaCy,honnibal/spaCy,honnibal/spaCy,spacy-io/spaCy,spacy-io/spaCy,explosion/spaCy,explosion/spaCy,spacy-io/spaCy,spacy-io/spaCy,explosion/spaCy,explosion/spaCy,spacy-io/spaCy,honnibal/spaCy,honnibal/spaCy,explosion/spaCy