[chore] [exporter/datasetexporter] Update metadata (#23885)

This pull request updates metadata for DataSet exporter. Metadata was
out of date and didn't reflect that the exporter plugin is distributed
as part of contrib.

---

NOTE: Per request in a PR review (atoulme), this change was moved out of
#23672
to a new and separate PR.

exporter/datasetexporter/README.md

@@ -4,9 +4,10 @@
 | Status        |           |
 | ------------- |-----------|
 | Stability     | [alpha]: logs, traces   |
-| Distributions | [] |
+| Distributions | [contrib] |
 
 [alpha]: https://github.com/open-telemetry/opentelemetry-collector#alpha
+[contrib]: https://github.com/open-telemetry/opentelemetry-collector-releases/tree/main/distributions/otelcol-contrib
 <!-- end autogenerated section -->
 
 This exporter sends logs to [DataSet](https://www.dataset.com/).

exporter/datasetexporter/metadata.yaml

@@ -4,4 +4,4 @@ status:
   class: exporter
   stability:
     alpha: [logs, traces]
-  distributions: []
+  distributions: [contrib]