Reduce size of group links in home page sidebar

This is just a small reduction to help compensate for having the list
pushed down by the donation goal. This list isn't intended to stay here
forever anyway.

tildes/scss/modules/_nav.scss

@@ -3,6 +3,8 @@
 
 .nav {
   li {
+    @include min-touch-size;
+
     margin-bottom: 0;
     font-size: 0.6rem;
     font-weight: bold;
@@ -43,3 +45,9 @@
     }
   }
 }
+
+.nav .nav-group-list {
+  li {
+    font-size: 0.7rem;
+  }
+}

tildes/tildes/templates/home.jinja2

@@ -54,7 +54,7 @@
         <li>Groups</li>
       {% endif %}
 
-      <ul class="nav">
+      <ul class="nav nav-group-list">
       {% for group in groups|sort %}
         <li class="nav-item"><a href="/~{{ group.path }}">~{{ group.path }}</a></li>
       {% endfor %}