Create coding samples for span outlining context behaviour

[lzchen]

Start [in]active span with implicit Context
Start [in]active span with explicit parent
Start inactive span and make it the active span in another process/thread/coroutine
For all of the above show setting baggage and where the set values are available

[ahlaw]

Could I take this issue?

[ahlaw]

Will this be part of the basic tracing runnable example or just a snippet in the "faq and cookbook" section?

[codeboten]

Ideally both.