Added corresponding example....not working yet.

added to_dot_test

not really useful yet...

Scenery::connect_nodes return () instead of EdgeIndex since it's not
needed anaywhere.

Remove example trait_test.
Doc fixes.

Source: add name parameter.

Update examples accordingly

Separate Dottable trait to additional file.

Add example for trait testing.

Update names of components in filter_test

This is only a preliminary solution until we have a general reporting.

Update docs. Update filter_test example.

Tiny doc fixes.

Add serde_yaml crate and add Serialize to spectrum.

Doc work.
Remove no unsed function in Light.

Add beam splitter to group. Analysis is still Ok.
Graph display still wrong.

Analysis seems to work. Display of graph wrong.

This simply forwards incoming LightResult.
Rename RefNode::new -> RefNode::from_node to fix clippy warnings.