Streamline tutorial docs

Fixes #634 
Replaces repetitive tutorials with an "Examples" section in "Getting Started", with much simplified structure and tutorials replaced with more minimal example Flocker config files and instructions.
@ferrantim I just want to clarify this comment before I make any change; are you saying you'd like to see two indexes to the same content. or two sections that split the content?
So I suppose I mean, would you like a features section that contains the two docs relating to environment vars and links in a feature section, but also have links to those same docs named as MySQL and ELK, sitting alongside Postgres in a technology section?