Graphical examples in introduction: text overlapping, requires specific font and font format

[dlesnoff]

We can barely see the first examples result, especially on larger screens (mine is 2560 x 1440). The window is by default 1920x1080, but it is hard to distinguish a pixel anyway.

The transparency is due to my compositor. If one does not have the correct font size, it overlaps with the lines. Would it be possible to hint at the correct font size for the graphical example to work correctly ? Could a picture of the expected result be integrated in the book or in the website ?

By default, it searches for the terminal font with a ttf extension. The program fails if one has installed only the otf version. Could you specify the expected font and font path ?