start stubbing out endpoints

app/routes/mod.py

@@ -0,0 +1,15 @@
+from flask import Blueprint
+
+bp = Blueprint('mod', __name__, url_prefix='/mod/')
+
+@bp.get('/')
+def index():
+    return 'stub'
+
+@bp.get('/topics/new')
+def new_topic():
+    return 'stub'
+
+@bp.get('/topics/sort')
+def sort_topics():
+    return 'stub'