Add transitous to this list

[isabelle-dr]

Add the https://github.com/public-transport/transitous project.
Referencing a message on MobilityData's slack:

At fosdem2024 a group of volunteers started transitous which strives for Europe wide transit routing based on opendata and opensource (motis).

[isabelle-dr]

@jbruechert, @vkrause, @EdwardBetts, do you want to open a PR to add this awesome project in this list?

:)

[vkrause]

We can certainly do that, although I'd maybe wait a bit until there's more to show :) Which section would this belong into though? It's somewhere between "Software for Creating APIs" and "Apps".

[isabelle-dr]

We will be re-organizing some of these sections, so you can pick one that kind of works and it will be perfect :)

Thank you for making this project available to the community 🤩