docs: Minor clean up of Phabricator documentation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165779 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/userguides.rst b/docs/userguides.rst
index 94f7218..8c1554d 100644
--- a/docs/userguides.rst
+++ b/docs/userguides.rst
@@ -19,6 +19,7 @@
    yaml2obj
    HowToSubmitABug
    SphinxQuickstartTemplate
+   Phabricator
 
 * :ref:`getting_started`