INGEST / Metrics, telemetry, and logs: Improve and modernize section

[amotl]

Problem

The tutorials section about how CrateDB integrates with other tools in the system metrics area is currently a bit flat, so it needs to be unflattened.

• https://cratedb.com/docs/guide/integrate/metrics/

Details

Those topics have been identified. Sure enough, there are many more.

• Anything about OpenTelemetry is missing dearly.
• The content about what the CrateDB Prometheus Adapter can do, is a bit thin. Just referencing it does not add much value other than, well, having the link.
• The page does not even mention the CrateDB JMX/Prometheus Exporter yet.
• Improve Connectivity with Telegraf jmx_exporter#63, and document it.
• Balance properly with the "integrations" page/section.

References

• https://github.com/crate/zk/issues/33

See also

• https://signoz.io/comparisons/opentelemetry-vs-telegraf/
• https://docs.oracle.com/en-us/iaas/releasenotes/stack-monitoring/telegraf12032025.htm
• https://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/CloudWatch-Agent-custom-metrics-collectd.html

[amotl]

Those patches will contribute relevant improvements to this section.

• Integrate/Telegraf: Add micro tutorial. Improve layout on index page. #267
• rsyslog: Index page and starter tutorial #305
• collectd: Index page and two usage guides #330
• StatsD: Index page and usage guide #332
• OpenTelemetry: Index page. Usage guides about OTel Collector and Telegraf. #334

[amotl]

The corresponding page has been improved significantly, see patches above.

• https://cratedb.com/docs/guide/ingest/telemetry/

However, the page still doesn't include anything about JMX yet, so let's follow up with another ticket.

• Crate JMX HTTP Exporter #366