add button to launch grocery app on home page

index.html

@@ -142,6 +142,23 @@
     </form>
   </div>
   <div class="pure-u-1-2 pure-u-sm-1-2 pure-u-md-1-3 pure-u-lg-1-4 l-box">
+    <form action="/grocery/trend"
+      id="grocery-trend" rel="external" method="get" target="_self">
+      <div class="card">
+        <button form="grocery-trend" style="color: tomato; border-color: tomato">
+          <input type="text" name="group" value="Fish, Meat, Eggs" hidden="true"/> 
+          <div class="image">
+            <h2>Grocery Chart</h2>
+          </div>
+          <div class="text">
+            <h3>Trending Prices</h3>
+	    <p>Plot charts showing historic price data</p>
+          </div>
+        </button>
+      </div>
+    </form>
+  </div>
+   <div class="pure-u-1-2 pure-u-sm-1-2 pure-u-md-1-3 pure-u-lg-1-4 l-box">
     <form action="https://shandan.one/pgadmin4"
       id="pgadmin" rel="external" method="get" target="_self">
       <div class="card">