List declarative config supported SDK extension plugin interfaces (#4452)

Explicitly state that declarative configuration should support
configuration of all SDK extension plugin interfaces, and list the
current status of all of them.

This idea came up in a recent [CNCF slack
discussion](https://cloud-native.slack.com/archives/C0476L7UJT1/p1742330526645349)
with @aabmass.

Author: jack-berg

CHANGELOG.md

@@ -32,6 +32,8 @@ release.
 
 - Convert declarative config env var substitution syntax to ABNF.
   ([#4448](https://github.com/open-telemetry/opentelemetry-specification/pull/4448))
+- List declarative config supported SDK extension plugin interfaces.
+  ([#4452](https://github.com/open-telemetry/opentelemetry-specification/pull/4452))
 
 ### Common
 

specification/configuration/sdk.md

@@ -9,6 +9,7 @@
   * [ConfigProvider](#configprovider)
   * [SDK extension components](#sdk-extension-components)
     + [ComponentProvider](#componentprovider)
+      - [Supported SDK extension plugins](#supported-sdk-extension-plugins)
       - [ComponentsProvider operations](#componentsprovider-operations)
         * [Create Plugin](#create-plugin)
   * [Config operations](#config-operations)
@@ -120,6 +121,31 @@ mechanism.
 See [create](#create), which details `ComponentProvider` usage in
 configuration model interpretation.
 
+##### Supported SDK extension plugins
+
+The [configuration data model](./data-model.md) SHOULD support configuration of
+all SDK extension plugin interfaces. SDKs SHOULD
+support [registration](#register-componentprovider) of custom implementations of
+SDK extension plugin interfaces via the `ComponentProvider` mechanism.
+
+The following table lists the current status of all SDK extension plugin
+interfaces in the configuration data model:
+
+| SDK extension plugin interface                                                              | Status                                                                             |
+|---------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------|
+| [resource detector](../resource/sdk.md#detecting-resource-information-from-the-environment) | +                                                                                  |
+| [text map propagator](../context/api-propagators.md#textmap-propagator)                     | +                                                                                  |
+| [span exporter](../trace/sdk.md#span-exporter)                                              | +                                                                                  |
+| [span processor](../trace/sdk.md#span-processor)                                            | +                                                                                  |
+| [sampler](../trace/sdk.md#sampler)                                                          | +                                                                                  |
+| [id generator](../trace/sdk.md#id-generators)                                               | - [#70](https://github.com/open-telemetry/opentelemetry-configuration/issues/70)   |
+| [pull metric reader](../metrics/sdk.md#metricreader)                                        | +                                                                                  |
+| [push metric exporter](../metrics/sdk.md#metricexporter)                                    | +                                                                                  |
+| [metric producer](../metrics/sdk.md#metricproducer)                                         | +                                                                                  |
+| [exemplar reservoir](../metrics/sdk.md#exemplarreservoir)                                   | - [#189](https://github.com/open-telemetry/opentelemetry-configuration/issues/189) |
+| [log record exporter](../logs/sdk.md#logrecordexporter)                                     | +                                                                                  |
+| [log record processor](../logs/sdk.md#logrecordprocessor)                                   | +                                                                                  |
+
 ##### ComponentsProvider operations
 
 The `ComponentsProvider` MUST provide the following functions: