Merge pull request #552 from martinjaggi/master. Closes #552.

tex formulas in the documentation

using mathjax.
and spliting the MLlib documentation by techniques

see jira
https://spark-project.atlassian.net/browse/MLLIB-19
and
https://github.com/shivaram/spark/compare/mathjax

Author: Martin Jaggi <m.jaggi@gmail.com>

== Merge branch commits ==

commit 0364bfabbfc347f917216057a20c39b631842481
Author: Martin Jaggi <m.jaggi@gmail.com>
Date:   Fri Feb 7 03:19:38 2014 +0100

    minor polishing, as suggested by @pwendell

commit dcd2142c164b2f602bf472bb152ad55bae82d31a
Author: Martin Jaggi <m.jaggi@gmail.com>
Date:   Thu Feb 6 18:04:26 2014 +0100

    enabling inline latex formulas with $.$

    same mathjax configuration as used in math.stackexchange.com

    sample usage in the linear algebra (SVD) documentation

commit bbafafd2b497a5acaa03a140bb9de1fbb7d67ffa
Author: Martin Jaggi <m.jaggi@gmail.com>
Date:   Thu Feb 6 17:31:29 2014 +0100

    split MLlib documentation by techniques

    and linked from the main mllib-guide.md site

commit d1c5212b93c67436543c2d8ddbbf610fdf0a26eb
Author: Martin Jaggi <m.jaggi@gmail.com>
Date:   Thu Feb 6 16:59:43 2014 +0100

    enable mathjax formula in the .md documentation files

    code by @shivaram

commit d73948db0d9bc36296054e79fec5b1a657b4eab4
Author: Martin Jaggi <m.jaggi@gmail.com>
Date:   Thu Feb 6 16:57:23 2014 +0100

    minor update on how to compile the documentation

1 files changed, 2 insertions, 2 deletions

diff --git a/docs/README.md b/docs/README.md
index dfcf753553..cc09d6e88f 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -10,9 +10,9 @@ We include the Spark documentation as part of the source (as opposed to using a
 
 In this directory you will find textfiles formatted using Markdown, with an ".md" suffix. You can read those text files directly if you want. Start with index.md.
 
-To make things quite a bit prettier and make the links easier to follow, generate the html version of the documentation based on the src directory by running `jekyll` in the docs directory. Use the command `SKIP_SCALADOC=1 jekyll` to skip building and copying over the scaladoc which can be timely. To use the `jekyll` command, you will need to have Jekyll installed, the easiest way to do this is via a Ruby Gem, see the [jekyll installation instructions](https://github.com/mojombo/jekyll/wiki/install). This will create a directory called _site containing index.html as well as the rest of the compiled files. Read more about Jekyll at https://github.com/mojombo/jekyll/wiki.
+To make things quite a bit prettier and make the links easier to follow, generate the html version of the documentation based on the src directory by running `jekyll build` in the docs directory. Use the command `SKIP_SCALADOC=1 jekyll build` to skip building and copying over the scaladoc which can be timely. To use the `jekyll` command, you will need to have Jekyll installed, the easiest way to do this is via a Ruby Gem, see the [jekyll installation instructions](http://jekyllrb.com/docs/installation). This will create a directory called _site containing index.html as well as the rest of the compiled files. Read more about Jekyll at https://github.com/mojombo/jekyll/wiki.
 
-In addition to generating the site as html from the markdown files, jekyll can serve up the site via a webserver. To build and run a webserver use the command `jekyll --server` which (currently) runs the webserver on port 4000, then visit the site at http://localhost:4000.
+In addition to generating the site as html from the markdown files, jekyll can serve up the site via a webserver. To build and run a local webserver use the command `jekyll serve` (or the faster variant `SKIP_SCALADOC=1 jekyll serve`), which runs the webserver on port 4000, then visit the site at http://localhost:4000.
 
 ## Pygments