[Feature] Show sum of the board scrum times at the top of the board

[MariusKlug]

Is your feature request related to a problem? Please describe. I have a weekly board and want to easily see the allocated time in this board.

Describe the solution you'd like To the top right could be the summed scrum times of the board. The "Scrum for trello" Extension has this (but is lacking a lot of your awesome features), e.g. here:

Ideally, this would include the pictograms and be centered in the top bar, like this:

[krzmig]

[GitHub][Feature] Show board scrum times