Sphinxify the outdated Packaging documentation.

llvm-svn: 158901
diff --git a/llvm/docs/userguides.rst b/llvm/docs/userguides.rst
index 57058ee..f1267dc 100644
--- a/llvm/docs/userguides.rst
+++ b/llvm/docs/userguides.rst
@@ -10,6 +10,7 @@
    DeveloperPolicy
    FAQ
    Lexicon
+   Packaging
 
 * `The LLVM Getting Started Guide <GettingStarted.html>`_
     
@@ -67,7 +68,7 @@
 
    Instructions for building the clang front-end from source.
     
-* `Packaging guide <Packaging.html>`_
+* :ref:`packaging`
 
    Advice on packaging LLVM into a distribution.