Consider adding more user interface to calendar tab

[hehug7]

The calendar works really good at the moment, but there could be difficult for the user to realize that the calendar is clickable. I'm thinking about leaving a small grey, italic text at the bottom of the tab page which says that the user can press on any tile to add a todo (even so this should be common sense).

On another note, when I want to add a todo when viewing the calendar, I would need to go to the tasks tab to add a new todo (let's say the date i 2025) since I dont want to click through the month after month. Yes, a user can easily add a todo with a different date by pressing on any tile, but should we consider adding another (+) button to the calendar like we did in the tasks tab to make it even easier to add todos?

[torjusti]

This won't make the cut for the initial release, as we only really need a minimum viable product.