add console as a supported env variable exporter type

This PR is a follow up to open-telemetry#3740 and open-telemetry#3741. As some languages (the ones I looked at were: python, js, ruby) already support the `console` type of exporter, I thought it would be good if the spec confirmed it.

Signed-off-by: Alex Boten <aboten@lightstep.com>

CHANGELOG.md

@@ -40,6 +40,8 @@ release.
 
 - Rename/replace `(client|server).socket.(address|port)` attributes with `network.(peer|local).(address|port)`.
   ([#3713](https://github.com/open-telemetry/opentelemetry-specification/pull/3713))
+- Add `console` as an exporter type that is supported via environment variable configuration.
+  ([#3742](https://github.com/open-telemetry/opentelemetry-specification/pull/3742))
 
 ### Supplementary Guidelines
 

specification/configuration/sdk-environment-variables.md

@@ -225,17 +225,20 @@ Known values for `OTEL_TRACES_EXPORTER` are:
 
 - `"otlp"`: [OTLP](../protocol/otlp.md)
 - `"zipkin"`: [Zipkin](https://zipkin.io/zipkin-api/) (Defaults to [protobuf](https://github.com/openzipkin/zipkin-api/blob/master/zipkin.proto) format)
+- `"console`: [Standard Output](../traces/sdk_exporters/stdout.md)
 - `"none"`: No automatically configured exporter for traces.
 
 Known values for `OTEL_METRICS_EXPORTER` are:
 
 - `"otlp"`: [OTLP](../protocol/otlp.md)
 - `"prometheus"`: [Prometheus](https://github.com/prometheus/docs/blob/master/content/docs/instrumenting/exposition_formats.md)
+- `"console`: [Standard Output](../metrics/sdk_exporters/stdout.md)
 - `"none"`: No automatically configured exporter for metrics.
 
 Known values for `OTEL_LOGS_EXPORTER` are:
 
 - `"otlp"`: [OTLP](../protocol/otlp.md)
+- `"console`: [Standard Output](../logs/sdk_exporters/stdout.md)
 - `"none"`: No automatically configured exporter for logs.
 
 ## Metrics SDK Configuration