Add Shiny Server to deployment section
Split deployment page into local and web

Also add info about runGitHub and runUrl
Add scoping section
Mention source(local=TRUE)
Clarify shared objects
Clarify global scope
Add understanding reactivity page
Edits and incorporate Hadley's suggestions
Split understanding reactivity
Fix code block typo
Convert all reactiveXX to renderXX and convert reactive functions to expressions
Convert code blocks to use templating format
Add note about reactive world
More detail in execution scheduling