Update toc.yml (#1074)

Renamed Setup to SetUp to match attribute name.

Author: southernsun

docs/articles/nunit/writing-tests/attributes/toc.yml

@@ -60,7 +60,7 @@
   href: setculture.md  
 - name: "[SetUICulture]"
   href: setuiculture.md  
-- name: "[Setup]"
+- name: "[SetUp]"
   href: setup.md  
 - name: "[SetUpFixture]"
   href: setupfixture.md