Minor cleanups

[Cobord]

• Fix up some of the doc comments (backticks)
• On options map and then unwraps are replaced with and_then, is_some_and, ...
• Be more explicit about casts to be clear when as would have been fallible vs infallible
• Panics and Error docs in format so they show up as their own sections
• Direct comparisons with Some(0)... instead of mapping and unwrapping
• Question about the outputs of .compile() never being used, would expect the Looped to use have Self::Output built from the C::Output(s)
• Instead of directly accessing graph.graph.node_weight, etc inspecting in fields of the struct have methods to do these common tasks. They are inlined methods on Graph instead.
• Tests assert in addition to printing. Want it to be testing properly even if don't --capture output
• A disjoint union of Graph and a test thereof. There are further things to discuss about GraphTensor with this point.

[jafioti]

What was cleaned up? Please provide details, there are many lines changed

[Cobord]

Not too much to say, but I will do so either tomorrow or Monday after can get back to this. Should have put as draft because didn't get to the description part yesterday before context switching.

[Cobord]

Any more documentation of what was done that you suggest?

[Cobord]

Let me know if there is any more wanted written here. This one is mostly about making more idiomatic. I find that once that happens it is much easier for me to add features without having the linter full of extraneous complaints.

[jafioti]

I don't think so, I just havent had a chance to review it yet because a good amount of lines were changed. Should have time today or this week!