[ENH]Screen to help tiki admins to setup search feature/s. New short sentences added willing to summarize the state of the art, and simple executive-summaries from all those sources of technical pages in dev about Search. Improvements welcome to help new tiki admins find their way to set up effective search configurations for their sites (if this is still confusing to experienced users, imagine newcomers...). Thanks jonnyb for feedback

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@47981 b456876b-0849-0410-b77d-98878d47e9d5