Saving and loading a project did not work with updates so I changed it so that you now need to add a frame on the docker and then save what's on the docker. You can then load up what you've recently been drawing.
One additional docker
Added one more docker for custom brushes below the image docker.
Docker visibility
Made the docker visible by adding frame sprites. On start and when the docker is visible, there is a help text that tells you to press "E" to enable or disable it.