add nan7market

_includes/block-grid.html

-<div class="block-grid">
+<div class="block-grid {{ include.extra_class }}">
   <a href="{{ include.url }}" target="_blank" title="{{ include.title }}">
     <div class="grid-title">{{ include.title }}</div>
     <div class="grid-icon">

index.html

@@ -107,6 +107,7 @@
                             {% include block-grid.html url="https://rec.ustc.edu.cn/" title="睿客网" icon="fad fa-swap-opacity fa-bookmark" %}
                             {% include block-grid.html url="https://welcome.ustc.edu.cn/" title="迎新网" icon="far fa-grin-wink" %}
                             {% include block-grid.html url="https://adrain.ustclug.org/" title="Admission Rain" icon="fad fa-graduation-cap" %}
+                            {% include block-grid.html url="https://nan7market.com/" title="南七集市" icon="fad fa-store" extra_class="new" %}
                             <div class="clear"></div>
                         </div>
                     </div>