Disable WordPress Block Editor Fullscreen Mode

Disable WordPress Block Editor Fullscreen Mode, activated by default in WordPress 5.4.

Full credit to Jean-Baptiste Audras for his blog on how to do this.
https://jeanbaptisteaudras.com/en/2020/03/disable-block-editor-default-fullscreen-mode-in-wordpress-5-4/

Active Contributors

Martin Wedepohl (Development)

Credits

• Thanks to Jean-Baptiste Audras for his blog on how to do this