Visual settings need to be documented #224

Orange version

3.34.0

Expected behavior

The documentation should contain explanations of the available visual settings for all widgets.

Actual behavior

There does not seem to be any documentation of the visual settings for the widgets – they are not always self-explanatory. E g, in the Line Plot widget there are settings for “Range” and “Selected range”. I thought these might adjust the boundaries for the Range in the Display settings, but apparently they represent the percentage of the grey scale value of the rendered Range. A pop-up would be fine.

Steps to reproduce the behavior

Go through the documentation pages at https://orangedatamining.com/widget-catalog/, notice the visual settings are not mentioned.
Open a widget and click the “Set visual settings” [a little redundant, eh?] button, hover over the settings, note no popups appear.

Additional info (worksheets, data, screenshots, ...)