Documentation
Major Description
Currently, all example snippets in the SQL programming guide are hard-coded, which can be pretty hard to update and verify. On the contrary, ML document pages are using the include_example Jekyll plugin to extract snippets from actual source files under the examples sub-project. In this way, we can guarantee that Java and Scala code are compilable, and it would be much easier to verify these example snippets since they are part of complete Spark applications.