Add markdown icon
<symbol id="accept" viewBox="0 0 24 24">
<path d="M9 16.172l10.594-10.594 1.406 1.406-12 12-5.578-5.578 1.406-1.406z"/>
</symbol>
+ <symbol id="markdown" viewBox="0 0 32 32">
+ <path d="M29.692 6h-27.385c-1.272 0-2.308 1.035-2.308 2.308v15.385c0 1.273 1.035 2.308 2.308 2.308h27.385c1.273 0 2.308-1.035 2.308-2.308v-15.385c0-1.272-1.035-2.308-2.308-2.308zM18 21.996l-4 0.004v-6l-3 3.846-3-3.846v6h-4v-12h4l3 4 3-4 4-0.004v12zM23.972 22.996l-4.972-6.996h3v-6h4v6h3l-5.028 6.996z"></path>
+ </symbol>
</defs>
</svg>
