Add chapter_3.rb to ch3 dir
Add chapter_3.js header
Add comments to Makefile
Complete understanding_dependencies, [36,41]
Finish isolate_instance_creation
Include design comments and update chapter links
Add default echo command to Makefile
Add three further examples - message isolation, init with hash args
Transfer relevant comments from Makefile -> TODO
Add gitignore file
Add two more code examples from poodr, use jasmine-node for testing