Please note that the editor is a communinity project maintained mostly by Julien Moreau.
The Babylon.js Editor is firstly available as a desktop application.
Note: It is highly recommanded to use the desktop app as you'll get access to the local file system to save your projects.
When an update is available (new features, bug fixes), you'll get notified and the editor will download the new installer for you.
This will also allow you to continue working even in offline mode and save projects directly on your local file system instead of using OneDrive. Basically, the online version must be just used as a playground or a scene explorer.