Document how to include Lazy class without runtime dependency

[sjoerdtalsma]

Give an introduction + example of the maven 'shade' plugin:

• explain the advantages of shading an ultra-light library such as Lazy4J
• provide a maven configuration that will shade the Lazy class into another package

[sjoerdtalsma]

Closing, as there has been exactly zero demand for this so far.
Perhaps in the future