better interop with #[instrument]

[rcoh]

currently, there isn't an easy way to examine a span if you don't have access to the span itself

[hawkw]

Does this work?

#[instrument]
fn whatever(something: usize) {
    tracing_texray::examine(Span::current().in_scope(|| {
       // do stuff
    });
}

I wonder if the in_scope() call is even necessary here since the span is already entered by the instrument call...

[rcoh]

probably but since it doesn't start tracking the span until the call to examine, we might miss the span being entered the first time, would need to try it out and see