Reorganise documentation for Elastic search

We as a support team do receive a lot of requests/issues related to Elastic Search and many of the times it is mainly because the user didn't read the documents completely or stop in the middle (once some part of the ES starts working) and misses the important part which is mentioned in the docs at the bottom.

For example: Indexing wikis

Can we reorganize our docs in such a way so the user doesn't miss the important parts of the setup?

cc// @axil @stanhu @nick.thomas @lbot @vsizov