Add button to hero detail page to pass funcitional test mentoined in previous commit

heroes/templates/detail_sunflowey.html

@@ -12,5 +12,7 @@
 <dt>Skills</dt><dd>Power Pellet, Sunshine, Pollen Punch</dd>
 <dt>Lore</dt><dd>I am Sunflowey. Sometimes a sun, sometimes a flower.</dd>
 </dl>
+
+<<a href="http://localhost:8000/heroes"><button>Back to Heroes List </button> </a>
 </body>
 </html>