Document NOT button in Binding Editor

Binding Editor now contains a button for creating a negative statement (NOT) when adding when statements for states.

Add this information to the Binding Editor documentation and other places where this is described:

• https://doc-snapshots.qt.io/qtdesignstudio-4.14/quick-property-bindings.html
• https://doc-snapshots.qt.io/qtdesignstudio-4.14/quick-scalable-image.html#using-states-to-change-component-property-values

Also include the table that lists logical operators to the Binding Editor topic:

https://doc-snapshots.qt.io/qtdesignstudio-4.14/quick-states.html#summary-of-logical-operators 

Use a .qdocinc file to make the table easy to maintain while displaying it in several places.