Built-in font for box drawing

[raphamorim]

When true, Rio will use a custom built-in font for box drawing
characters (Unicode points U+2500 - U+259F), legacy computing symbols
(U+1FB00 - U+1FB3B), and powerline symbols (U+E0B0 - U+E0B3).

builtin-box-drawing = true

sextant symbols from U+1FB00 to U+1FB3B

Ref: alacritty/alacritty@b48ab14

https://github.com/alacritty/alacritty/blob/b48ab148ff54c7e2e816765840568614d9e966f9/alacritty/src/renderer/text/builtin_font.rs#L49-L587

[TomLebeda]

Would it be possible to include Braille symbols into the pretty aligned rendering as well please?

There are visible gaps between lines of Braille symbols, at some font sizes more visible than others. I have tried many terminals and Wezterm is the only one that renders Braille symbols neatly aligned so that lines are not recognizable.

I'm including some images to illustrate what I mean.