Document the level of support exist for OpenTracing JS

[carlosalberto]

OpenTracing JS never implemented ScopeManager, which supports in-process context propagation. This means that only explicit context/Span propagation is supported, even if OpenTelemetry offers this.

cc @yurishkuro @mwear @open-telemetry/javascript-approvers

[bogdandrutu]

@dyladan ?

[dyladan]

This appears to be true. There was an issue in opentracing to add a scope manager, but it doesn't look like it was ever implemented opentracing/opentracing-javascript#112

What is our action item here? Should we just document on the shim that there is no scope manager so we have no shim for it?

[yurishkuro]

Yes, we simply need to be compatible with existing status of OT

[carlosalberto]

Closing, this was all addressed by #2230 (now we only need to document this in each related SIG, e.g. Javascript SIG)