[SPARK-8517][ML][DOC] Reorganizes the spark.ml user guide

This PR moves pieces of the spark.ml user guide to reflect suggestions in SPARK-8517. It does not introduce new content, as requested.

<img width="192" alt="screen shot 2015-12-08 at 11 36 00 am" src="https://cloud.githubusercontent.com/assets/7594753/11666166/e82b84f2-9d9f-11e5-8904-e215424d8444.png">

Author: Timothy Hunter <timhunter@databricks.com>

Closes #10207 from thunterdb/spark-8517.

1 files changed, 7 insertions, 8 deletions

diff --git a/docs/mllib-guide.md b/docs/mllib-guide.md
index 43772adcf2..3bc2b78060 100644
--- a/docs/mllib-guide.md
+++ b/docs/mllib-guide.md
@@ -66,15 +66,14 @@ We list major functionality from both below, with links to detailed guides.
 
 # spark.ml: high-level APIs for ML pipelines
 
-**[spark.ml programming guide](ml-guide.html)** provides an overview of the Pipelines API and major
-concepts. It also contains sections on using algorithms within the Pipelines API, for example:
-
-* [Feature extraction, transformation, and selection](ml-features.html)
+* [Overview: estimators, transformers and pipelines](ml-intro.html)
+* [Extracting, transforming and selecting features](ml-features.html)
+* [Classification and regression](ml-classification-regression.html)
 * [Clustering](ml-clustering.html)
-* [Decision trees for classification and regression](ml-decision-tree.html)
-* [Ensembles](ml-ensembles.html)
-* [Linear methods with elastic net regularization](ml-linear-methods.html)
-* [Multilayer perceptron classifier](ml-ann.html)
+* [Advanced topics](ml-advanced.html)
+
+Some techniques are not available yet in spark.ml, most notably dimensionality reduction 
+Users can seemlessly combine the implementation of these techniques found in `spark.mllib` with the rest of the algorithms found in `spark.ml`.
 
 # Dependencies