Redo documentation

[oubiwann]

Features & Tasks:

• Provide Updated README - Provide Updated README #29
• Add documentation for working with nodes in the REPL - Add documentation for working with nodes in the REPL #32
• Add documentation for starting JVM nodes from LFE - Add documentation for starting JVM nodes from LFE #33
• Add documentation for managing nodes with a supervision tree - Add documentation for managing nodes with a supervision tree #34

Part of release #20 (0.4.0)