Constant UTF8_BORDERS_ONLY

pub const UTF8_BORDERS_ONLY: &str = "││──╞══╡     ──┌┐└┘";

Just like the UTF8_FULL style, but without vertical/horizontal middle lines.

┌───────────────┐
│ Hello   there │
╞═══════════════╡
│ a       b     │
│ c       d     │
└───────────────┘