For some characters (eg \r) the returned glyph will have .{.rows = 0, .width=0, .pitch = 0, .buffer = null}. In zig null[0..0] causes a panic rather than returning an empty slice.
General mach examples use ``long-example-name`` case but freetype was
using ``snake_case`` right now, which is inconsistent and midly
inconvenient to use.
Renamed: glyph_to_svg -> glyph-to-svg, single_glyph -> single-glyph
