typo
typos
fix example: if readyState is already complete, resolve
add missing var in an example
tweak example
simplify the example, drop ready()
add a note about main document authoring in JS vs HTML+JS
an implementation detail
add a note about the 'other' reason
add a note re message passing between apps
typo
clarify expectations re resubscription on launch
s/read/register/
add a note re persistent event handling onlaunch; fix a typo in an example
note re default visibility if the main document is authored in HTML
credits
move 'Persistent Events' section under 'Infrastructure'