added hyperlink to homepage and author views

bookshelf/templates/bookshelf/books.html

@@ -6,4 +6,8 @@
     {% for books in books %}
         <a href="http://127.0.0.1:8000/books/{{ books.pk }}">{{ books.title }}</a><br>
     {%  endfor %}
+    <br>
+    <a href="http://127.0.0.1:8000/homepage/">Home</a>
+    &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
+    <a href="http://127.0.0.1:8000/authors/">Authors</a>
 {% endblock %}
\ No newline at end of file