Option to change font size in the reader pane

[jarekkopec]

I would love to be able to increase the font size in the reader pane, by which I mean the pane to the right on this screenshot (framed with the red rectangle).

I think that the icon allowing for increasing/decreasing the font size in the top right corner, where the arrow points.

I think it would allow the user to configure a comfortable reading experience, increasing the accessibility of the app.