Allow us to add an emoji font or specify fallback fonts

I was trying out HTTPie on my terminal and after running the hello world example I realized that my font (source code pro) didn't have emojis. I tried to add emojis but quickly realized that meant that I would have to choose an entirely differen't font for everything.

If we can specify multiple fonts or add a font specifically for emojis, I could import something like android emojis while still keeping my preferred font