mkdocs-material/material/.icons/fontawesome/solid/window-maximize.svg

<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><!--! Font Awesome Free 6.4.0 by @fontawesome - https://fontawesome.com License - https://fontawesome.com/license/free (Icons: CC BY 4.0, Fonts: SIL OFL 1.1, Code: MIT License) Copyright 2023 Fonticons, Inc.--><path d="M64 32C28.7 32 0 60.7 0 96v320c0 35.3 28.7 64 64 64h384c35.3 0 64-28.7 64-64V96c0-35.3-28.7-64-64-64H64zm32 64h320c17.7 0 32 14.3 32 32s-14.3 32-32 32H96c-17.7 0-32-14.3-32-32s14.3-32 32-32z"/></svg>