See #662 for explanation of Tesseract.js Version 4 changes.  List below is auto-generated from commits. 

* Added image preprocessing functions (rotate + save images)

* Updated createWorker to be async

* Reworked createWorker to be async and throw errors per #654

* Reworked createWorker to be async and throw errors per #654

* Edited detect to return null when detection fails rather than throwing error per #526

* Updated types per #606 and #580 (#663) (#664)

* Removed unused files

* Added savePDF option to recognize per #488; cleaned up code for linter

* Updated download-pdf example for node to use new savePDF option

* Added OutputFormats option/interface for setting output

* Allowed for Tesseract parameters to be set through recognition options per #665

* Updated docs

* Edited loadLanguage to no longer overwrite cache with data from cache per #666

* Added interface for setting 'init only' options per #613

* Wrapped caching in try block per #609

* Fixed unit tests

* Updated setImage to resolve memory leak per #678

* Added debug output option per #681

* Fixed bug with saving images per #588

* Updated examples

* Updated readme and Tesseract.js-core version