Hide Completed Subtasks Option

[darthmachina]

A similar way as #16 to reduce the amount of subtasks shown, it would be nice to have the option to hide completed subtasks so they no longer appear on the card.

If the subtask is completed on the board I would introduce a delay between completing it and hiding it, as that would allow the user to uncheck the checkbox if it was checked by mistake without having to go and edit the task directly.

[roovo]

As per #16 - I'll add the the next milestone (although the delay may have to be a future enhancement depending on how simple it is to add)

[roovo]

thanks !!

[darthmachina]

Question: should tags on subtasks be included on the card if the subtask is completed? My initial thought is no since the tag applied to the subtask and not the main task, so it's probably not relevant anymore. But that is treating tags a bit like GTD contexts, so there might be a use case for the tag to still apply.

@roovo Do you have a preference either way?