Add a counter for Done tasks in the project pages

It has many advantages in my opinion:

• You can see directly how many tasks- do you already did in this project

• You can easily click on it and see all of them

• It is very motivating (for me) to see a number (hey, I made 15 times Sport since I used Akiflow! :))

And its similar to the today-view.

Hope you will like it too! :)

Thanks for your good support and work Francesco!

Best regards

Stefan