src/components/gui/add-tab.svg

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg width="20px" height="20px" viewBox="0 0 20 20" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
    <line x1="4" x2="16" y1="10" y2="10" style="stroke:#777;stroke-width:3;" stroke-linecap="round" />
    <line x1="10" x2="10" y1="4" y2="16" style="stroke:#777;stroke-width:3;" stroke-linecap="round" />
</svg>