Fix inconsistent tracestate reference

[PerfectSlayer]

Changes

I just would like to report that all links to W3C tracestate specifications are either:

• https://www.w3.org/TR/trace-context/#tracestate-header or,
• https://www.w3.org/TR/trace-context/#tracestate-header-field-values

But specification/overview.md is using:

• https://w3c.github.io/trace-context/#tracestate-field (not the same document/version).

Do you need me to open an issue first?

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: PerfectSlayer / name: Bruce Bujon (65a7e2d)
• ✅ login: reyang / name: Reiley Yang (7d41a4a)

[carlosalberto]

It seems https://w3c.github.io/trace-context/#tracestate-field is pointing to the most recent version (a draft), which indeed is probably not what we want. Maybe @dyladan has some insight into the different links?

[dyladan]

Indeed you most likely don't want the draft unless you're specifically referencing draft features like the random flag.