du-scrollspy - better documentation for observation behavior about angular-scroll

[oblador]

Hi, I've updated the documentation to correctly describe the current functionality. Making all elements that's currently in the viewport would make the directive put active classes on all elements at the same time. I think it's pretty rare that you'd want that, but could maybe be added as an option if there's more interest. For the no active class issue that could be solved with a "greedy" option (to be implemented).

[rayshan]

Thanks. For my use case (table of content for documentation) I agree it would be confusing for the user if a lot of elements are highlighted at the same time. Perhaps someone else would have a different use case.