mkdocs-material/material/.icons/fontawesome/solid/folder-plus.svg

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><path d="M464 128H272l-64-64H48a48 48 0 0 0-48 48v288a48 48 0 0 0 48 48h416a48 48 0 0 0 48-48V176a48 48 0 0 0-48-48zM359.5 296a16 16 0 0 1-16 16h-64v64a16 16 0 0 1-16 16h-16a16 16 0 0 1-16-16v-64h-64a16 16 0 0 1-16-16v-16a16 16 0 0 1 16-16h64v-64a16 16 0 0 1 16-16h16a16 16 0 0 1 16 16v64h64a16 16 0 0 1 16 16z"/></svg>