Add table with Gateway versions (#361)

* Add table with Gateway versions

* Update docs/reference/edot-collector/config/default-config-standalone.md

Co-authored-by: Carson Ip <[email protected]>

* Update default-config-standalone.md

---------

Co-authored-by: Carson Ip <[email protected]>

Author: theletterf

docs/reference/edot-collector/config/default-config-standalone.md

@@ -97,9 +97,15 @@ In Gateway mode, the Collector ingests data from other Collectors running in Age
 
 ## Sample configuration
 
-The following sample configuration file is available for the Gateway mode:
-
-- [Gateway mode]
+The following sample configuration files are available for the Gateway mode:
+
+| Version | Configuration  |
+|---------|----------------|
+| 8.17    | [Gateway mode](https://raw.githubusercontent.com/elastic/elastic-agent/refs/tags/v9.0.3/internal/pkg/otel/samples/linux/gateway.yml) |
+| 8.18    | [Gateway mode](https://raw.githubusercontent.com/elastic/elastic-agent/refs/tags/v9.0.3/internal/pkg/otel/samples/linux/gateway.yml) |
+| 9.0     | [Gateway mode](https://raw.githubusercontent.com/elastic/elastic-agent/refs/tags/v9.0.3/internal/pkg/otel/samples/linux/gateway.yml) |
+% | 8.19    | [Gateway mode](https://raw.githubusercontent.com/elastic/elastic-agent/refs/tags/v8.19.0/internal/pkg/otel/samples/linux/gateway.yml) |
+% | 9.1     | [Gateway mode](https://raw.githubusercontent.com/elastic/elastic-agent/refs/tags/v9.1.0/internal/pkg/otel/samples/linux/gateway.yml) |
 
 Use the previous example configuration as a reference when configuring your Gateway Collector or customizing your EDOT Collector configuration.