[SPARK-13015][Docs] Replace example code in mllib-data-types.md using include_example

[keypointt]

Replace example code in mllib-data-types.md using include_example
https://issues.apache.org/jira/browse/SPARK-13015

The example code in the user guide is embedded in the markdown and hence it is not easy to test. It would be nice to automatically test them. This JIRA is to discuss options to automate example code testing and see what we can do in Spark 1.6.

Goal is to move actual example code to spark/examples and test compilation in Jenkins builds. Then in the markdown, we can reference part of the code to show in the user guide. This requires adding a Jekyll tag that is similar to https://github.com/jekyll/jekyll/blob/master/lib/jekyll/tags/include.rb, e.g., called include_example.
{% include_example scala/org/apache/spark/examples/mllib/LocalVectorExample.scala %}
Jekyll will find examples/src/main/scala/org/apache/spark/examples/mllib/LocalVectorExample.scala and pick code blocks marked "example" and replace code block in
{% highlight %}
in the markdown.

See more sub-tasks in parent ticket: https://issues.apache.org/jira/browse/SPARK-11337

[mengxr]

ok to test

[mengxr]

cc @yinxusen

[SparkQA]

Test build #51142 has finished for PR 11128 at commit d580fe7.

• This patch fails Python style tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #51160 has finished for PR 11128 at commit 33cbe1b.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #51600 has finished for PR 11128 at commit c6280c2.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #51647 has finished for PR 11128 at commit 6c454c7.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #51797 has finished for PR 11128 at commit a1b57f5.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #52536 has finished for PR 11128 at commit 02b4e22.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[yinxusen]

@keypointt Examples in the PR are all small ones. I am not sure whether we merge them or not. Either we use this PR #9430 to rewrite it, or we just leave this markdown file unchanged. @mengxr What do you think about it?

[srowen]

What's the resolution here -- just leave these as-is?

[yinxusen]

@keypointt How about we close this for now? There are too many small example codes. If we need all example codes out of markdown files, we can reopen it then. Thanks so much and sorry about that!

[keypointt]

@yinxusen sure, no problem. I'm closing it.