Create Documentation for Bundle Graph

[chrisrueger]

In PR bndtools/bnd#7106 we implemented a new View to display a Graph of bundles.

Please generate a web page for this at the same level as _manual/jareditor.md (rendered as https://bndtools.org/manual/jareditor.html) which is located under the secion "User Interface" in the left navbar.

As a screenshout you could use this:

The page should contain in user-friendly language the features of this graph view and a section for use-cases.