From the official docs:
```
Note: The official Debian and Ubuntu images automatically run apt-get clean, so explicit invocation is not required.
```
Also added ` && rm -rf /var/lib/apt/lists/*` as part of the install line which probably does what was intended (no need to make a new layer).
Added apt-get update to the RUN payload, as it should be part of the same layer.
Both are documented here: https://docs.docker.com/engine/userguide/eng-image/dockerfile_best-practices/
Using only one layer, and activating it with two keys at the moment.
As with previous comments, this isn't final, but is a good starting point for a one-handed keyboard, half a Planck-like ortholinear keyboard, or a sample to show a layout with a function layer.
Ryan MacLeanandJack Humbert
