start stubbing out endpoints

app/routes/threads.py

@@ -0,0 +1,11 @@
+from flask import Blueprint
+
+bp = Blueprint('threads', __name__, url_prefix='/threads/')
+
+@bp.get('/<slug>')
+def thread(slug):
+    return 'stub'
+
+@bp.get('/new')
+def new():
+    return 'stub'