chore: add basic tracer example (#277)
chore: add basic tracer example (#277)


open-telemetry/opentelemetry-js,open-telemetry/opentelemetry-js,open-telemetry/opentelemetry-js-contrib,open-telemetry/opentelemetry-js,open-telemetry/opentelemetry-js-contrib,open-telemetry/opentelemetry-js-contrib,open-telemetry/opentelemetry-js-contrib,open-telemetry/opentelemetry-js