now using jinja2 block / template, rather than jscript to fill content

templates/authors.html

@@ -1,3 +1,6 @@
+{% extends "base.html" %}
+
+{% block main_content %}
 <h3>Authors</h3>
 <table id="book_table" class="table table-striped table-sm" data-toolbar="#toolbar" data-search="true">
 	<thead>
@@ -11,3 +14,4 @@
 	{% endfor %}
 	</tbody>
 </table>
+{% endblock main_content %}