`Span` references `LoggingContext` in its docs

[fabianfett]

/// A `Span` represents an interval from the start of an operation to its end, along with additional metadata included
/// with it. A `Span` can be created from a `Baggage` or `LoggingContext` which MAY contain existing span identifiers,
/// in which case this span should be considered as "child" of the previous span.

We should remove the ref to LoggingContext here.

[slashmo]

I'm pretty sire that's not the only reference to the "old" context propagation mechanism. Konrad already started updating the documentation, not sure though if this particular reference was already removed: #69

[ktoso]

Yeah this will be solved by the docs rewrite, ongoing here: #69

Since you also have a few things we can fix right away perhaps the plan forward is to keep merging and releasing 0.x things until we're happy and you've had a chance to try out those versions :-)