Add UniFMU to tools list

[sagilar]

Added entry for the tool UniFMU by Aarhus University.

[chrbertsch]

Thanks for adding your tool!
I think the Aarhus University logo is missing. Could you please add it to https://github.com/sagilar/fmi-standard.org/tree/add-unifmu/static/assets/images/logos, best in SVG format?

(It would be great if you could provide provide compatibility information (see https://github.com/modelica/fmi-standard.org/blob/main/CONTRIBUTING.md#compatibility-information), i.e. how you tested your FMI implementation?
Could also be in a separate Pull Request.
Benefit for you: your tool will get the "yellow star" and be listed on the top.)

[sagilar]

I've added the svg logo as requested and linked the tool logo entry to it. I also added the original one provided by the university, which is in eps format (aulogo_uk_var1_blue.eps) in case it's needed.
I'll check the compatibility information and push it in a different PR.