Add details to Asynchronous Gauge API (#1703)
Add details to Asynchronous Gauge API (#1703)

* add details to asynchronous gauge

* Update specification/metrics/api.md

Co-authored-by: Cijo Thomas <242191b8c991f635fefc07748c2f69af50b38db4@microsoft.com>

* Update specification/metrics/api.md

Co-authored-by: Cijo Thomas <242191b8c991f635fefc07748c2f69af50b38db4@microsoft.com>

* Update specification/metrics/api.md

Co-authored-by: Cijo Thomas <242191b8c991f635fefc07748c2f69af50b38db4@microsoft.com>

* Update specification/metrics/api.md

Co-authored-by: Joshua MacDonald <f3bd74e7fbbcca8170a843c74945d604f45dfc0a@users.noreply.github.com>

Co-authored-by: Cijo Thomas <242191b8c991f635fefc07748c2f69af50b38db4@microsoft.com>
Co-authored-by: Joshua MacDonald <f3bd74e7fbbcca8170a843c74945d604f45dfc0a@users.noreply.github.com>
Co-authored-by: Sergey Kanzhelev <dd2a78e617335ac05535a01af404ce3eb19c30fd@live.com>
open-telemetry/opentelemetry-specification,open-telemetry/opentelemetry-specification