add sum of estimated total reading time

Hi!

It would be great to have an idea of how many articles there are left to read in the app, and especially how long it will take to read them. There could be a little widget like there is in AntennaPod, a podcast client for Android, for example:


In the above, notice the line on top of the queue that says "4 episodes, 9 hours and 42 minutes". That's pretty neat! It gives me a clear idea of how much "listening" i have queued up so if I leave for a long train ride or car ride, I know if I will have enough to pass the time (or not).

I keep thinking the Wallabag android app should do the same, so i figured I would bring it up here.

Thank you for this great program!