Add page showing list of series

Resolves: #17

main.py

@@ -269,6 +269,14 @@ order by num
     return database.session.execute(sql)
 
 
+@app.route("/series")
+def list_series() -> str:
+    """Page showing list of conference series."""
+    items = model.Series.query
+
+    return flask.render_template("series/list.html", items=items)
+
+
 @app.route("/speakers")
 def top_speakers_page() -> str:
     top = top_speakers()