Set up Dark mode

[theperu]

As discussed on Discord it wouldn't take much to implement a dark mode on the app.
I would also add an option to turn it on/off from our settings, I would create a card similar to the ones that we have and that would change the theme when you tap on it. Maybe we could also change the icon between a sun and a moon when a user taps on it but it all depends on the effort required

[andreadelsarto]

I can go with this