Create official logo/symbol for Muban

[skulptur]

We are using this project widely, and having a logo would give it more professionalism. My main use case for now is in internal communication such as presentations and slack emoji. Having some stickers/mugs/t-shirts made wouldn't hurt either. We should also use that as default favicon.

The image bellow is a screenshot of how the name is currently displayed in the project's website. I like the general vibe, and suggest we use that as a starting point. We should also have a symbol or compact version to allow for the common use cases I mentioned earlier.

[pigeonfresh]

I'm not sure about the current workload of our Illustration teams. But perhaps we could make it a challenge?