They use this package under the hood: https://github.com/jdxcode/smooth-progress https://github.com/jdxcode/smooth-progress It uses glyphs of boxes that have v

They use this package under the hood: https://github.com/jdxcode/smooth-progress https://github.com/jdxcode/smooth-progress It uses glyphs of boxes that have varying widths. When joined together, they appear as a solid bar.