Enlarge tasks list

[lukateras]

First of all, thank you so, so, so much for this extension. Your extension made it possible for me to use Thunderbird. I couldn't have used it otherwise. Thanks <3

It would be nice if it proportionally enlarged tasks list too. Currently it looks like this even with this addon enabled:

In case if you are not interested in implementing this yourself, I might be able to find time to take a stab at this if you are interested in merging this change!