Font option

[tomchen]

• Add bold card desc option (Font size option (make it bold) #72)
• Add more font set to choose:

Existing font sets:
Normal, Erathian

To add:

Pixel font set (#44):

• Choose a pixel font with good coverage of Latin & Cyrillic letters
• For CJK and other characters, use subsetted vectorized GNU Unifont (Wikipedia)

And more maybe

Then move Erathian option from language window to visual preference window.

[tomchen]

#72 done but it's just "bold font" checkbox now, maybe we can add more options