default generated graph hard to view

[manuel-freire]

When running degraph without arguments, it generates a huge graphml file with what appear to be scala's dependencies.

Attempting to open this graph with graph editors such as Gephi (which reports ~10k nodes and complains on most properties) or yEd (which understands the nesting, but still shows nothing useful, even after some tinkering) results in unreadable graphs. As far as defaults go, it is not specially informative, and may be more appropriate as a stress test than an example.

A simpler example would be a better (and gentler) introduction to the tool.