Improve documentation for Views integration

Information on Views integration should be added to the handbook page. Something like the text in the readme file (minus the typo on "Go"):

Weight includes a default view that provides a drag-and-drop interface for reordering nodes. Go to Administration > Structure > Views, locate the disabled Weight view, and click enable. This view can now be edited as normal to fit your needs.

Node weights can also be used in new or existing views as Filters, Sorts, or Arguments.

Please also clarify that node weight is global (since the Weight module uses the node table's sticky column), and therefore affects the ordering of nodes with a weight assigned to them in any list on a site, no matter if it is the default front page or custom views. (As opposed to e.g. DraggableViews which stores its information in separate tables so that one node may have different "weights" in different views.)

At least that is my current understanding.