Support: Flatastic

Heyhey!
I did implement support for [flatastic](https://www.flatastic-app.com/en/). It's a household organization app that includes "household tasks", as well as a shopping list. My integration only supports household tasks, not the shopping list (because I think it does not make too much sense). It's basically a list of recurring tasks that you can tick. However, I'm not sure whether that integration "crosses a line" in the sense of definitely not being a bugtracker, and afaik all the other bugwarrior integrations are bug trackers (except gmail)?
Also, a few other things like annotations do not make sense (there are no comment functionalities in flatastic).

It's useful for me and in a state that is "good enough for me" currently. I could improve it and make it available for others as well if you think it makes sense. What's your point of view?

Cheers,
Lena