Fix syntax errors in example code snippets

doc/introduction.rst

@@ -280,7 +280,7 @@ When your forms contain foreign keys, have those **related models loaded via aja
 
     form_ajax_refs = {
         'user': {
-            'fields': ['first_name', 'last_name', 'email']
+            'fields': ['first_name', 'last_name', 'email'],
             'page_size': 10
         }
     }
@@ -474,7 +474,7 @@ To generate the URL for a specific view, use *url_for* with a dot prefix::
 
     class MyView(BaseView):
         @expose('/')
-        def index(self)
+        def index(self):
             # Get URL for the test view method
             user_list_url = url_for('user.index_view')
             return self.render('index.html', user_list_url=user_list_url)

flask_admin/model/base.py

@@ -513,7 +513,7 @@ class BaseModelView(BaseView, ActionsMixin):
             class MyModelView(BaseModelView):
                 form_ajax_refs = {
                     'user': {
-                        'fields': ('first_name', 'last_name', 'email')
+                        'fields': ('first_name', 'last_name', 'email'),
                         'page_size': 10
                     }
                 }