`DotColoredDigraph` documentation is broken

[mtorpey]

I was looking at the documentation for DotDigraph, which includes variants such as DotColoredDigraph, and the examples included are problematic. For some reason they're a <Log> instead of <Example>, so they're not executed by the automated tests – running them manually results in an error.

They're also weirdly formatted, with several graphs declared in a row without being used, they're extremely lengthy and verbose, and there are too many of them.

I might fix this soon if no one else does, since it's required for DotColoredEdgeWeightedDigraph (#746). But it occurs to me that it's quite a beginner-friendly task in case any newcomers want to try it.

[coraaked]

I'd be keen to have a look at this!