HSEARCH-1644

Docs updates ! :-)
 - https://hibernate.atlassian.net/browse/HSEARCH-1644

I'm not sure either. I agree the explanation gets off-topic from the main point which is to get Hibernate Search running.
Could we keep it as separate JIRA?
I also would like to start the first chapter with a "what prolems does this solve" introduction rather than straight to getting started, so there is more to do anyway