[docs] We need to add some documentation 1 - user manuals - Scriptis

[Adamyuanyuan]

For most new users, our current document is not comprehensive enough and the document format is not standard. What users need most is user manuals, such as:

• Scripts:
  • Scala: includes Spark Core/UDF/UDAF
  • PySpark
  • SparkSQL
  • HiveSQL ......
• Schedulis:
• Visualis: ......

And first we'd like to add some user manuals to scripts in docs*\ch3 .