[#1377] Add docs for snippet API example
[#1377] Add pubsub example and docs
[#1377] Add stubs for remaining sections of js tutorial
[#1377] Fix the case of a title
[#1377] Add best practice about not overusing pubsub
[#1377] Add pubsub working example

This should have been in commit e46df2a6e2cab4326080d50b958b9554284a5bc2
[#1377] Add overview to top of js tutorial
[#1377] Add note about when js modules are initialized