Document how the arguments are used and shown in the Qt Insight Web Console

When users see the documentation of a Qt Insight Tracker API, such as "interaction"(https://doc.qt.io/qtinsighttracker/qml-qtinsighttracker-insighttracker.html#interaction-method), they see something like this:

interaction(string name, const QString &contextKey, double contextValue, string category)

Send a interaction event name with additional context data. Context data can be sent as a key/value pair in contextKey and contextValue. The optional category parameter can be used to filter tracking of the events. 

The problem is, they could have no clue about how the arguments would be used and shown in the Qt Insight Web Console. For example, what "contextKey" should be and how it's displayed in the Qt Insight Web Console. Without that knowledge, it's difficult for the user to properly use the APIs. 

I suggest that we should add this kind of information where necessary, for all relevant APIs' documentation.