analytics: measure usage of keyboard shortcuts and other features

[broady]

Trigger an event when keyboard shortcuts are used:

https://developers.google.com/analytics/devguides/collection/gajs/methods/gaJSApiEventTracking

Probably here:

gddo/gddo-server/assets/site.js

Lines 174 to 207 in 72a348e

	if (combo) {
	switch (prevCh + ch) {
	case "gg":
	$('html,body').animate({scrollTop: 0},'fast');
	return false;
	case "gb":
	$('html,body').animate({scrollTop: $(document).height()},'fast');
	return false;
	case "gi":
	if ($('#pkg-index').length > 0) {
	$('html,body').animate({scrollTop: $("#pkg-index").offset().top},'fast');
	return false;
	}
	case "ge":
	if ($('#pkg-examples').length > 0) {
	$('html,body').animate({scrollTop: $("#pkg-examples").offset().top},'fast');
	return false;
	}
	}
	}
	switch (ch) {
	case "/":
	$('#x-search-query').focus();
	return false;
	case "?":
	$('#x-shortcuts').modal();
	return false;
	case "f":
	if ($('#x-jump').length > 0) {
	$('#x-jump').modal();
	return false;
	}
	}

[broady]

To collect stats via GA on clicking through to source, it looks like upgrading to analytics.js might be required. I don't think the legacy ga.js gives you a callback after the event was tracked.