Sketchbook missing

[PaulStoffregen]

Describe the bug
The sketchbook list does not appear in the File menu.

To Reproduce
Use Arduino 1.8.10 and save some sketches.

Then run this new IDE and click the File menu. No sketchbook list.

Expected behavior
I was expecting the new IDE to find my sketchbook location from the old IDE and show it in a similar way.

Desktop (please complete the following information):
Linux, Ubuntu 18.04, 64 bit

[PaulStoffregen]

Also looks like saving a few defaults to a location, rather than where I had configured my sketchbook using File > Preferences in the old IDE.

[mastrolinux]

The sketchbook is visible in the open file icon.

[kittaakos]

It's under File > Sketchbook.