[SPARK-6806] [SPARKR] [DOCS] Add a new SparkR programming guide

This PR adds a new SparkR programming guide at the top-level. This will be useful for R users as our APIs don't directly match the Scala/Python APIs and as we need to explain SparkR without using RDDs as examples etc.

cc rxin davies pwendell

cc cafreeman -- Would be great if you could also take a look at this !

Author: Shivaram Venkataraman <shivaram@cs.berkeley.edu>

Closes #6490 from shivaram/sparkr-guide and squashes the following commits:

d5ff360 [Shivaram Venkataraman] Add a section on HiveContext, HQL queries
408dce5 [Shivaram Venkataraman] Fix link
dbb86e3 [Shivaram Venkataraman] Fix minor typo
9aff5e0 [Shivaram Venkataraman] Address comments, use dplyr-like syntax in example
d09703c [Shivaram Venkataraman] Fix default argument in read.df
ea816a1 [Shivaram Venkataraman] Add a new SparkR programming guide Also update write.df, read.df to handle defaults better

1 files changed, 1 insertions, 0 deletions

diff --git a/docs/_layouts/global.html b/docs/_layouts/global.html
index b92c75f90b..eebb3faf90 100755
--- a/docs/_layouts/global.html
+++ b/docs/_layouts/global.html
@@ -75,6 +75,7 @@
                                 <li><a href="mllib-guide.html">MLlib (Machine Learning)</a></li>
                                 <li><a href="graphx-programming-guide.html">GraphX (Graph Processing)</a></li>
                                 <li><a href="bagel-programming-guide.html">Bagel (Pregel on Spark)</a></li>
+                                <li><a href="sparkr.html">SparkR (R on Spark)</a></li>
                             </ul>
                         </li>